The White House on Sunday insisted that sanctions against Russia, over the crisis in Ukraine, would work in the long term. The comments, made by the deputy national security adviser Tony Blinken, came after President Obama, on a visit to Malaysia, sought to solidify European support for such measures.

Obama told reporters: “We're going to be in a stronger position to deter [Russian president Vladimir] Putin when he sees that the world is unified and the United States and Europe is unified rather than this is just a US-Russian conflict.”

In the Ukrainian city of Slavyansk on Sunday, eight military observers from the Organisation for Security and Cooperation in Europe who have been held by pro-Russian separatists for three days were presented to the press by their captors. One of the observers, a Swede, was later released.

Blinken, asked on CNN's State of the Union – the first of three Sunday morning talkshows on which he appeared – whether the Obama administration was able to influence events in any way, said: “A week ago, Russia signed on to a roadmap regarding the events in Ukraine. Unfortunately, it hasn't lived up to that.

“So the president, in Asia, by phone convened all of the senior European leaders and got them to agree to a very strong statement, and this week there will be additional sanctions on Russia.”

Asked what would hurt Putin the most, Blinken said the White House aimed to undermine the president's “promise” to the Russian people, of delivering economic growth.

“The economic isolation of Russia is growing everyday,” he said. “It's financial markets are down 22% since the beginning of the year.”

Regarding the focus of the new sanctions, however, he added: “Starting this week, in co-ordination with our allies and partners, we'll be exerting additional pressure on people closest to Putin, the companies they control, the defence industry, all of this.”

Washington and Brussels are expected, possibly as early as Monday – Blinken later told CBS the new measures would “begin to roll out as early as tomorrow” – to name new people and firms to be hit by punitive measures. In Malaysia, Obama said any decision on wider sanctions would depend on whether the US and its allies could find a unified position.

Washington is more hawkish on further sanctions than the European Union, as many European countries are worried about the risks involved, not least because Europe has extensive business ties with Moscow and imports about a quarter of its natural gas from Russia.

Bob Corker of Tennessee, the ranking Republican on the Senate foreign relations committee, told CBS's Face the Nation the sanctions against Russia needed to have a wider focus.

“These targeted sanctions against individuals just are not affecting Putin's behaviour,” he said. “We need to start hitting companies within Russia … [to] destabilise their economy.



“I hope tomorrow's sanctions are much stronger than just against individuals. Much tougher sanctions need to be put in place.

“The Russian economy is certainly very fragile. To me, hitting four of the largest banks there would send shockwaves into the economy. Hitting Gazprom would certainly send shockwaves in the economy.

“What I fear is all we're doing is tweaking folks, these are oligarchs. We really aren't affecting the upper middle class, a broader base of citizens.”

Obama said Russia had not "lifted a finger" to get pro-Russian separatist rebels in Ukraine to comply with an international agreement to defuse the crisis. "In fact, there's strong evidence that they've been encouraging the activities in eastern and southern Ukraine," he said.



On Saturday, the US secretary of state, John Kerry, and the Russian foreign minister, Sergei Lavrov, spoke by phone. Each urged the other to do more to control contending interests in Ukraine.

On CNN, Blinken was asked why the administration was not considering providing weapons to Ukraine, in order for it to resist Russia's intervention more effectively. This week the Ukrainian prime minister, Arseny Yatsenyuk, said Russia wanted to “start world war three”, and added that "attempts at military conflict in Ukraine will lead to a military conflict in Europe."

Defending US policy of providing non-lethal aid, Blinken said: “We're focusing on where we can be most effective. This week the IMF programme [of aid] is going to go forward and all told, we're looking at $37bn over two years. That's going to have a dramatic impact."

“The vice-president [Joe Biden] was in Ukraine just a week ago – he announced additional, non-lethal security assistance. We've also worked with Ukraine before this crisis to help professionalise their military.

“But here's the bottom line – we could send weapons to Ukraine but it would not make a difference to their ability to stand up to the Russians.”