Zelensky didn't reveal much detail about an updated plan, although he said there needed to be more investment for drones.

Russia launched its largest barrage of drones and missiles in a month across Ukraine, killing at least three people, Ukrainian President Volodymyr Zelensky said Saturday, as a Kyiv delegation heads to the United States for fresh peace talks.

Certainly, the latest rounds of American bargaining and pressure on Ukraine are the most substantial yet. “This isn’t another round of what we saw before,” says a Western diplomat in Kyiv. Those close to the talks speak of “serious progress” bringing some Ukrainian and Russian positions together.

Ukraine’s chief negotiator, in an exclusive interview, says conceding sovereign territory is off-limits in peace talks.

Russian drone and missile attacks in and around the Ukraine's capital killed at least three people early Saturday, officials said, as the country's representatives traveled to the U.S. to work on a renewed push to end the war.

"None of us really know what Zelenskyy is like operating solo, because he never has," one expert told NBC News.

Russian President Vladimir Putin said that a US plan to end the war in Ukraine could “form the basis for future agreements” but renewed threats to seize more territory by force unless Kyiv withdraws.

President Donald Trump's top officials are meeting with a team of Ukrainian negotiators. Trump has been trying to broker an end to Russia's war in Ukraine since he took office.