But Tuesday’s meeting in Kyiv, , was a rare in-person gathering for Mr. Zelensky and outside leaders. So far, the fighting has been focused in the suburbs of the capital as the military prepares to defend Kyiv from a possible assault. At least one attendee wore a green protective vest while sitting at the table with Mr. Zelensky, according to a photograph posted on the president’s official website.

Mr. Zelensky also invited other world leaders to join him in Kyiv, and once again pressed allies to enforce a no-fly zone over the country, which they have resisted out of concerns of being drawn into a direct conflict with Russia.

“I invite all friends of Ukraine to visit Kyiv,” Mr. Zelensky said in a statement posted on his official Telegram channel. “It can be dangerous here. Because our sky is not yet closed to Russian missiles and planes.”