KYIV, June 17 - Foreign Minister Dmytro Kuleba said on Thursday he welcomed U.S. President Joe Biden's tough messaging when he met President Vladimir Putin this week and said now was the time to make Russia withdraw from Ukraine, Reuters reported.

In the first high-level Ukrainian government reaction since the Biden-Putin summit in Geneva on Wednesday, Kuleba told Reuters that the talks had not caused any concern for Kyiv.

"This summit demonstrated that America is back, and now it's time to make Russia pull back from Ukraine," Kuleba said in an interview, adding that Moscow has no power of veto over Ukraine's accession to NATO.

Kyiv had been wary of the prospect of Biden and Putin cutting a deal about Ukraine's future behind its back.

"President Putin saw... no invitation to bargain from the United States on the Ukrainian matter," Kuleba said. "And this is a matter of principle because we agreed with the United States that no deals on Ukraine will be made without Ukraine, and America kept its promise."

Moscow's annexation of the Crimean peninsula from Ukraine in 2014 and its support for separatists in eastern Ukraine are among a number of factors that have badly strained relations between Russia and the United States in recent years.

President Volodymyr Zelenskiy told Reuters this week he had received reassurances from Biden that Ukraine would not be used as a bargaining tool.

Zelenskiy has urged NATO members to accelerate Ukraine's bid to join the alliance after a standoff with Moscow this year that saw Russia mass additional troops and military equipment near Ukraine's borders.

The Kremlin said on Thursday that this would be a 'red line' for Russia.

Kyiv has been frustrated by the apparent reluctance of some European members of NATO - keen not to antagonize Moscow - to admit Ukraine.

Even Biden, while pledging support for Ukraine's territorial integrity, told a NATO summit in Brussels on Monday that Ukraine must root out corruption and meet other criteria before it can join the alliance.

Kuleba said Ukraine was stepping up its verbal pressure on NATO because it remains "in a security vacuum" even as it battles the Russian-backed separatists in its east.

"We are not members of any security alliance... So yes, we are a nation desperately seeking security. And this prompts us to be active, to be pushy, if I may," Kuleba added.

Biden will host Zelenskiy at the White House in July. (rt/ez)