The crews of all three merchant vessels seized by the U.S. military over the past week are still in U.S. custody.
The assassination of the second leader of the Islamic Republic, who had no designated successor, would throw its future into doubt.
Almost 15,000 Ukrainian civilians have been killed and just over 40,000 injured since the start of the war through last December.
Russia puts death toll from Ukrainian strike at 27 as Zelenskyy names intelligence chief to new role
Russian authorities say a Ukrainian drone strike on a café in the Kherson region has killed 27 people.
President Trump said he would consider extending U.S. security guarantees for Ukraine beyond 15 years, according to President Zelenskyy.
Monday's hastily assembled meeting comes after President Trump met on Friday with Russian President Vladimir Putin in Alaska.
Presidents Trump and Putin are holding a press conference following their meeting in Alaska to discuss ending the Russia-Ukraine war.
A dozen leaders from Europe and Canada are in Ukraine’s capital to mark the third anniversary of Russia’s invasion.
Russia and the U.S. have agreed to start working toward ending the war in Ukraine and improving their diplomatic and economic ties.
Fighting around nuclear power plants has repeatedly raised fears of a nuclear catastrophe during three years of war.