Story highlights Obama, Putin speak about Ukraine

Biggest group yet of 70 Dutch and Australian experts spends day at crash site

Dutch officials say all remains found Friday will be taken to the Netherlands

"We hope that this will bring some solace for the next of kin," says Dutch official

The grisly search for human remains from Malaysia Airlines Flight 17 entered a new phase Friday, as the largest group yet of international experts scoured the crash site in eastern Ukraine.

In total, 70 Dutch and Australian experts reached the scene, many more than had made it there previously in the two weeks since the crash, in which 298 people lost their lives.

The Organization for Security and Co-operation in Europe, whose monitors escorted the experts on their difficult mission, said via Twitter that "substantial recovery efforts" had been made.

"We are happy that we can make sure that these corpses can now be transported to the Netherlands," said Pieter-Jaap Aalbersberg, head of the Dutch recovery mission.

"We hope that this will bring some solace for the next of kin. It is a relief for our people that they have now started their work."

Friday's visit to the site has been completed and all human remains found will be brought back, the Dutch Ministry of Security and Justice said in a statement. The Netherlands is leading the international investigation.

Over the past two days, the international team has taken a different route to reach the crash site, after days of fighting between Ukraine's military and pro-Russia rebels prevented their access.

High-level negotiations with both sides made it possible for the experts' convoy of vehicles to cross and recross the front lines to approach from the north, helped by a brief break in the hostilities in the area.

Aalbersberg said the recovery team is now on its way to a new base in the town of Soledar, to the northwest of the rural location in eastern Ukraine where MH17 came down on July 17, strewing debris across a huge area.

The mission will still have personnel in the cities of Kharkiv and Donetsk, the latter a rebel stronghold that has seen fighting this week.

Second victim identified

On Thursday, when just four experts made it to the site alongside eight monitors, they marked locations where they spotted human remains, OSCE spokesman Michael Bociurkiw said.

He said then that they might use cadaver dogs and aerial surveillance to search the scene when they returned Friday.

"This all goes back to time is of the essence," he told CNN's Anderson Cooper late Thursday. "Everyone realizes that time is no longer on our side, that this investigation has to kick-start into high gear right away."

Many coffins holding remains -- collected in the first week after the disaster -- already have been flown to the Netherlands, where the Malaysia Airlines flight originated.

There, in the city of Hilversum, more than 200 forensic specialists are working to identify the individual victims from the remains found.

The Dutch Ministry of Security and Justice said Friday that the identity of a second victim had been confirmed. The relatives of the victim, a Dutch citizen, have been informed, as has victim's local mayor, the statement said.

The painstaking and heartbreaking task of identifying every victim could take months, the Dutch authorities have warned. About two-thirds of those killed were Dutch, with Malaysians and Australians making up a large proportion of the others.

As many as 80 bodies could still be lying in the fields of eastern Ukraine where the passenger jet crashed, Australia's Foreign Minister Julie Bishop told CNN on Thursday.

"But we won't know until our investigative teams are on the site and combing the crash site for remains," Bishop said. "And that's the grisly and sobering task that they must undertake from now on."

Ukraine's parliament approved agreements Thursday that allow international personnel from countries that had citizens on Flight 17 to work at the crash site. Up to 700 of them can be armed.

Talks on crisis held in Belarus

A one-day cease-fire declared by the Ukrainian military ended Friday morning, but Ukrainian Deputy Prime Minister Volodymyr Groysman said it would seek to maintain a halt in hostilities on the route to the crash site.

Overnight, 10 Ukrainian paratroopers were killed near Shakhtarsk, less than 25 kilometers (15 miles) from the crash area, when their convoy came under attack from pro-Russia rebel forces, according to the Facebook page of Ukraine's Counter-Terrorist Operation.

Eight bodies have been evacuated so far, and the troops have been pulled out to a safer area, the Facebook post said. The militants have prevented recovery of two other bodies by constantly firing at the site, it added.

Photos: Malaysia Airlines Flight 17 crashes in Ukraine Photos: Malaysia Airlines Flight 17 crashes in Ukraine Debris from Malaysia Airlines Flight 17 sits in a field at the crash site in Hrabove, Ukraine, on September 9, 2014. The Boeing 777 was shot down July 17, 2014, over Ukrainian territory controlled by pro-Russian separatists. All 298 people on board were killed. In an October 2015 report, Dutch investigators found the flight was shot down by a warhead that fit a Buk rocket, referring to Russian technology, Dutch Safety Board Chairman Tjibbe Joustra said. Hide Caption 1 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Australian and Dutch experts examine the area of the crash on August 3, 2014. Hide Caption 2 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A woman walks with her bicycle near the crash site on August 2, 2014. Hide Caption 3 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Police secure a refrigerated train loaded with bodies of passengers from Malaysia Airlines Flight 17 as it arrives in a Kharkiv, Ukraine, factory on July 22, 2014. Hide Caption 4 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A pro-Russian rebel passes wreckage from the crashed jet near Hrabove on Monday, July 21, 2014. Hide Caption 5 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine – Wreckage from the jet lies in grass near Hrabove on July 21, 2014. Hide Caption 6 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A man covers his face with a rag as members of the Organization for Security and Co-operation in Europe and the Dutch National Forensic Investigations Team inspect bodies in a refrigerated train near the crash site in eastern Ukraine on July 21, 2014. Hide Caption 7 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Emergency workers carry a victim's body in a bag at the crash site on July 21, 2014. Hide Caption 8 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A piece of the plane lies in the grass in eastern Ukraine's Donetsk region on July 21, 2014. Hide Caption 9 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine An armed pro-Russian rebel stands guard next to a refrigerated train loaded with bodies in Torez, Ukraine, on Sunday, July 20, 2014. Hide Caption 10 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Ukrainian State Emergency Service employees sort through debris on July 20, 2014, as they work to locate the deceased. Hide Caption 11 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A woman covers her mouth with a piece of fabric July 20, 2014, to ward off smells from railway cars that reportedly contained passengers' bodies. Hide Caption 12 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Toys and flowers sit on the charred fuselage of the jet as a memorial on July 20, 2014. Hide Caption 13 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine People search a wheat field for remains in the area of the crash site on July 20, 2014. Hide Caption 14 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A woman walks among charred debris at the crash site on July 20, 2014. Hide Caption 15 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Emergency workers load the body of a victim onto a truck at the crash site on Saturday, July 19, 2014. Hide Caption 16 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Emergency workers carry the body of a victim at the crash site on July 19, 2014. Hide Caption 17 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A large piece of the main cabin is under guard at the crash site on July 19, 2014. Hide Caption 18 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Victims' bodies are placed by the side of the road on July 19, 2014, as recovery efforts continue at the crash site. International officials lament the lack of a secured perimeter. Hide Caption 19 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A man looks through the debris at the crash site on July 19, 2014. Hide Caption 20 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine An envelope bearing the Malaysia Airlines logo is seen at the crash site on July 19, 2014. Hide Caption 21 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Armed rebels walk past large pieces of the Boeing 777 on July 19, 2014. Hide Caption 22 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Ukrainian rescue workers walk through a wheat field with a stretcher as they collect the bodies of victims on July 19, 2014. Hide Caption 23 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A woman looks at wreckage on July 19, 2014. Hide Caption 24 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Pro-Russian rebels stand guard as the Organization for Security and Co-operation in Europe delegation arrives at the crash site on Friday, July 18, 2014. Hide Caption 25 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A woman walks through the debris field on July 18, 2014. Hide Caption 26 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Pro-Russian rebels stand guard at the crash site. Hide Caption 27 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Wreckage from Flight 17 lies in a field in Shaktarsk, Ukraine, on July 18, 2014. Hide Caption 28 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A man covers a body with a plastic sheet near the crash site on July 18, 2014. The passengers and crew hailed from all over the world, including Australia, Indonesia, Malaysia, Germany and Canada. Hide Caption 29 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A diver searches for the jet's flight data recorders on July 18, 2014. Hide Caption 30 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Coal miners search the crash site. Hide Caption 31 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Wreckage from the Boeing 777 lies on the ground July 18, 2014. Hide Caption 32 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine People search for bodies of passengers on July 18, 2014. Hide Caption 33 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A woman walks past a body covered with a plastic sheet near the crash site July 18, 2014. Hide Caption 34 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Belongings of passengers lie in the grass on July 18, 2014. Hide Caption 35 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine People inspect the crash site on Thursday, July 17, 2014. Hide Caption 36 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine People walk amid the debris at the site of the crash. Hide Caption 37 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Debris smoulders in a field near the Russian border. Hide Caption 38 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Fire engines arrive at the crash site. Hide Caption 39 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A man stands next to wreckage. Hide Caption 40 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Debris from the crashed jet lies in a field in Ukraine. Hide Caption 41 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Family members of those aboard Flight 17 leave Schiphol Airport near Amsterdam, Netherlands. Hide Caption 42 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A large piece of the plane lies on the ground. Hide Caption 43 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Luggage from the flight sits in a field at the crash site. Hide Caption 44 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A couple walks to the location at Schiphol Airport where more information would be given regarding the flight. Hide Caption 45 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Flight arrivals are listed at the Kuala Lumpur International Airport in Sepang, Malaysia. Hide Caption 46 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Debris from the Boeing 777, pictured on July 17, 2014. Hide Caption 47 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A man inspects debris from the plane. Hide Caption 48 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Wreckage from the plane is seen on July 17, 2014. Hide Caption 49 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A man talks with security at Schiphol Airport on July 17, 2014. Hide Caption 50 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine Wreckage burns in Ukraine. Hide Caption 51 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A man stands next to the wreckage of the airliner. Hide Caption 52 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine People inspect a piece of wreckage believed to be from Malaysia Airlines Flight 17. This image was posted to Twitter Hide Caption 53 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine People inspect a piece of wreckage believed to be from Malaysia Airlines Flight 17. This image was posted to Twitter. Hide Caption 54 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A piece of wreckage believed to be from Malaysia Airlines Flight 17. This image was posted to Twitter Hide Caption 55 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A piece of wreckage believed to be from MH17. This image was posted to Twitter Hide Caption 56 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine An airsickness bag believed to be from MH17. This image was posted to Twitter Hide Caption 57 of 58 Photos: Malaysia Airlines Flight 17 crashes in Ukraine A piece of wreckage believed to be from MH17. This image was posted to Twitter Hide Caption 58 of 58

Ukrainian National Security and Defense Council spokesman Andriy Lysenko said at a briefing Friday that Russia was "actively preparing firing positions for shelling Ukrainian territory" and has positioned 17 Grad rocket systems in its Bryansk region, about three miles from the border with Ukraine, according to Ukraine's Ukrinform news agency.

Senior representatives of Ukraine, Russia and OSCE, known as the Trilateral Contact Group, held talks on the crisis Thursday in Belarus with representatives of the eastern Ukraine rebel groups.

The participants "committed to securing further safe access to international investigators to the crash site until the investigation activities on the spot are completed," a statement from the Trilateral Contact Group said.

They also discussed the situation of hostages taken during the three-month-long conflict and agreed to the release "of a sizable number of persons deprived of freedom," it said.

Former Ukrainian President Leonid Kuchma told the news agency Interfax-Ukraine on Friday that 20 people would be freed "in the near future."

He was also quoted as saying a promise had been made to transfer the personal belongings of those killed on Flight 17, currently still strewn across the crash area.

The rebels and Trilateral Contact Group agreed to continue the talks -- held at the initiative of Ukrainian President Petro Poroshenko -- next week.

Russian remains defiant

U.S. and Ukrainian officials have alleged that a Russian-made missile system downed the plane from rebel-held territory; Russia and the rebel fighters deny involvement.

Ukrainian and Western leaders also accuse Russia of continuing to arm and support the rebels since the plane's downing, an allegation Moscow rejects.

In a bid to crank up pressure on Russia to rein in the rebels, Europe and the United States imposed new sanctions this week aimed at disrupting activity in Moscow's banking, oil and arms industries.

But Russia, while warning that the sanctions will harm relations and damage the European economy as much as its own, has remained defiant.

Russian state news agency Itar-Tass cited Vladimir Chizhov, Russia's EU ambassador, as saying Friday that his country's banking sector "will face certain difficulties" but that its economy "has sufficient resources to tackle these problems."

U.S. concerns

Obama spoke Friday with Putin and underscored "his deep concerns about Russia's increased support for the separatists in Ukraine," the White House said.

"The President reinforced his preference for a diplomatic solution to the crisis in Ukraine, and the two leaders agreed to keep open their channels of communication. The President also reiterated his concerns about Russia's compliance with its obligations under the INF Treaty," the White House said.

The Kremlin said Putin and Obama agreed on the need for an immediate end to hostilities in eastern Ukraine and the need to continue dialogue. Sanctions against Russia are counterproductive, Putin told Obama during a telephone conversation initiated by the United States on Friday, the Kremlin said in a statement.

U.S. Vice President Joe Biden spoke Friday with Poroshenko.

Biden announced about $8 million in new assistance to the Ukrainian State Border Guard Service. It includes "engineering equipment for improving infrastructure along Ukraine's borders, transport and patrol vehicles, surveillance equipment to extend the visual range of border security patrols, and small boats to conduct maritime patrol and interdiction operations."