Russia and Turkey agreed to boost economic ties on Wednesday as Moscow hailed improving bilateral relations following tensions caused by Ankara's shooting down of a Russian fighter jet near the Syrian border in 2015.

However, there was little obvious progress on Syria, where the two countries back opposing sides, as Russian President Vladimir Putin hosted his Turkish counterpart Recep Tayyip Erdogan in the Russian city of Sochi for talks that had been expected to focus on the conflict.

"The recovery process in Russian-Turkish ties is complete," Putin said during a joint news conference held by the two leaders. "We are getting back to a normal cooperative partnership."

Russia had retaliated against Turkey with a raft of economic sanctions in 2015 after the Russian jet was shot down, and Ankara later took retaliatory measures.

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Putin said Russia would launch a joint investment fund with Turkey with funds of up to $1bn, and that they would seek to boost energy cooperation. Moscow also stood ready to help Turkey to improve security measures at its tourist resorts, said Putin.

Russia and Turkey have reached a comprehensive agreement to lift sanctions, Putin said. But the exact date of the removal of some sanctions is not clear.

Political solutions

Both leaders affirmed a commitment to seeking a political solution to the Syrian conflict through dialogue.

Russia, Turkey and Iran have been brokering Syria peace talks in Kazakhstan. Russia and Iran are major military backers of Syrian President Bashar al-Assad, whereas Turkey supports certain rebel groups seeking to overthrow him.

The two leaders met as the latest round of talks began in Kazakhstan's capital, Astana. The meeting is supposed to pave the way for safe - or "de-escalation" - zones in Syria to mitigate the humanitarian crisis.

During Wednesday news conference, Erdogan said he hoped "this zone of de-escalation will be accepted" at the talks.

Putin stated that the idea of creating safe zones to protect civilians in Syria from fighting has wide support, but further discussions are needed to work out the details of how they would operate.

"We both proceed on the basis that - and this is our common position - the creation of safe zones should lead to further pacification and cessation of hostilities," said Putin.

Al Jazeera's Stefanie Dekker, reporting from Sochi, said Putin and Erdogan's press remarks had revealed no new details in terms of the conflict in Syria.

"Reading behind the lines it seemed that there wasn't much consensus on Syria, but this is just speculation because they didn't give us anything concrete," said Dekker.

"I think we are going to have to shift our focus to Astana over the next two days to see if anything was achieved here behind closed doors," she added.

Astana talks

But the talks in the Kazakh capital got off to a rocky start as the opposition delegation suspended its participation in protest against ongoing air raids in the war-torn country.

Syrian rebel and government delegations were discussing a Russian plan for "de-escalation zones" on Wednesday when the opposition walked out, citing the bombardment of rebel-held areas.

"They aren't fully withdrawing participation. They've walked out of the meetings but they haven't left - at least not yet," said Al Jazeera Jamal Elshayyal, reporting from Astana.

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Fadi Hakura, a Turkey expert at the UK-based think-tank Chatham House, told Al Jazeera that the bilateral talks had not clarified whether Russia would remove trade sanctions against Turkish agricultural exports or ease visa restrictions on Turkish citizens visiting Russia.

"To paraphrase Shakespeare, it's much-a-talk about nothing. We saw a lot of discussion on process and procedures but nothing concrete was reached in those discussions," said Hakura.

On Syria, Hakura said that both leaders had repeated their commitments to discussion and to contain the conflict.

"But fundamentally the main disagreement is that Russia favours regime stability, Turkey prefers regime change," said Hakura. "And until, and unless, this fundamental disagreement is resolved, we will not see any concrete achievements."

Flurry of diplomacy

It has been a busy few days of international diplomacy for Putin.

Tensions between the Russian leader and US President Donald Trump appeared to be easing as the two men expressed desire for a ceasefire in Syria during a phone call on Tuesday.

This was their first known conversation since Trump ordered missile strikes on a Syrian airbase last month, a move that outraged Moscow.

A White House statement said that the "very good" phone discussion included improving prospects for cooperation in Syria and a focus on setting up safe zones in the country.

Trump will host Erdogan on May 16-17 at the White House, in the first meeting between the two leaders.

Putin hosted German Chancellor Angela Merkel for talks in Sochi on Tuesday, in which they re-affirmed their commitment to the Minsk agreement for resolving the conflict in eastern Ukraine.

Putin said there was "no alternative to the Minsk deal", while Merkel stressed that "implementation is a problem, not the agreement itself".

The accord was signed by Ukraine, Russia, Germany and France in February 2015 in the Belarusian capital of Minsk to stop the fighting in eastern Ukraine and withdraw heavy weapons 15km on either side of the frontline. It also says local elections must be held in the breakaway regions of Donetsk and Luhansk.