The comment comes after President Donald Trump urged Zelensky to "get moving" on securing a peace deal with Russia, who he claimed wants to make a deal, and said if Zelensky does not move fast "he'll miss a great opportunity.

NPR's Scott Simon speaks to Fiona Hill, senior fellow at the Brookings Institution's Center on the United States and Europe, about the Trump administration's strategy to end Russia's war with Ukraine.

In the nearly four years since Russia’s unprovoked full-scale invasion of Ukraine, the war has repeatedly confounded expectations. A conflict that many analysts anticipated would be short and devastating for Kyiv has proved prolonged and costly for both sides.

Dispatches from Ukraine. Day 1448.

Ukrainian President Volodymyr Zelensky has said that the United States wants a peace settlement between Ukraine and Russia by early summer, despite repeated rounds of talks failing to reach a breakthrough over the issues of territory and security guarantees.

It is unclear what the Trump administration is prepared to do if it does not get the concessions it wants from Kyiv on issues like territory and elections.

"My feeling is that the member states are not ready to give a concrete date," Kallas told a panel at the Munich Security Conference. "There's a lot of work to be done."

Donald Trump said he would be involved in nuclear talks with Iran getting underway Tuesday but warned of "consequences" if Tehran doesn't make a deal.