The Kremlin warned Thursday that there was "not much cause for optimism” that the West would satisfy Russia’s demands in the showdown over Ukraine, but said that President Vladimir Putin would take his time to study the written responses that the United States and NATO submitted a day earlier before deciding how to proceed.

"All these papers are with the president,” Putin’s spokesman, Dmitry Peskov, told reporters. "There will of course be some time needed to analyze them — we won’t rush to any conclusions.”

The Biden administration on Thursday called a meeting of the U.N. Security Council on Monday to discuss the crisis, which could make for a rare, face-to-face debate on Ukraine between the United States and Russia.