US President Joe Biden held talks Thursday first with Ukrainian President Volodymyr Zelenskyy and then NATO allies in eastern Europe in the hopes of deescalating tensions just one week after US intelligence warned of a possible Russian invasion of Ukraine. 

After the call, Zelenskyy tweeted, "The President of the United States informed me of the content of his negotiations with Putin."

He added, "We also discussed possible formats for resolving the conflict in Donbass and touched upon the course of internal reforms in Ukraine." 

Following the call with Zelenskyy, Biden spent 40 minutes on the line with leaders from fellow NATO allies Bulgaria, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania and Slovakia.

Afterwards Asta Skaisgiryte, a Lithuanian presidential advisor, told reporters in Vilnius that Biden had told leaders there would be "nothing about you without you" when it came to negotiations between Russia and Ukraine.

What was discussed during the calls with Biden?

Biden and Zelenskyy spoke for more than an hour on Thursday.

A statement from Zelenskyy's office said the Ukrainian leader had discussed with Biden ways to provide financial and political support to Ukraine.

Zelenskyy said his nation had "clear proposals" on how to return to peace talks with Russia over the eastern Donbass region seized by Moscow-backed forces in 2014.

US national security advisor Jake Sullivan acknowledged Ukraine's proposals Thursday.

"Ukrainians have come forward with constructive ideas for how to move the diplomacy forward," Sullivan said.

Biden has said it is "not on the table" to send US troops into Ukraine but when it comes to protecting the countries on NATO's eastern front, the White House says quite the opposite.

What are the challenges confronting Biden?

Biden has a tricky balance to play as Ukraine wants to join NATO. While the country is about a decade or more out from that goal, US and NATO reject the notion that Putin should get a vote in who will join the political and military alliance.

The White House also hopes it can convince Kyiv to accept some de facto on the ground realities in eastern Ukraine and do so without the appearance of a Putin victory.

Any perception of American weakness could incite Putin to press his luck given his penchant for risk, analysts say. At the same time, Washington says Ukraine's sovereignty and territorial integrity are not up for negotiation.

Alexander Vershbow, a former US ambassador to Moscow, told AP: "It has to be very much in lockstep with the Ukrainians, not behind their backs, or forcing them to accept a distasteful compromise."

The Biden administration has said if Russia invades Ukraine, it will face the toughest sanctions it has to date.

ar/wd (AFP, AP, Reuters)