Two U.S. senators are warning that Russian President Vladimir Putin is stalling on peace while preparing a fresh military offensive against Ukraine.

With 41 military aircraft impacted, the Ukrainian drone attack was described by some commentators as Russia's "Pearl Harbor." The attack on Pearl Harbor in December 1941 was a surprise air raid by Japan on the U.S. during World War II. Kyiv's assault follows ground advances by Moscow troops in recent days in Ukraine's Sumy border region.

A bipartisan pair of US senators met with Ukrainian President Volodymyr Zelensky in Kyiv on Friday and urged stronger sanctions against Russia, while uncertainty swirls over whether the next round of peace talks will move ahead in the coming days.