Ukrainian President Volodymyr Zelensky has landed at Joint Base Andrews, beginning his first visit outside of his country since Russia invaded Ukraine 300 days ago, according to a White House official.

Zelensky is set to meet with President Biden at the White House this afternoon before addressing a joint session of Congress this evening, and the official said the events are tracking on time.

“I am in Washington today to thank the American people, the President and the Congress for their much-needed support,” Zelensky wrote on Telegram alongside photos of his arrival. “And also to continue cooperation to bring our victory closer. I will hold a series of negotiations to strengthen the resilience and defense capabilities of Ukraine.”

Zelensky was greeted upon landing by Oksana Markarova, Ukraine’s ambassador to the U.S., and Rufus Gifford, chief of protocol at the State Department.

Flight data shows a U.S. Air Force plane landed at Joint Base Andrews, located in the suburbs of Washington, D.C., shortly after noon after taking off from Rzeszow, Poland, which is located near the Ukrainian border.

Polish television station TVN24 posted footage of Zelensky in Rzeszow, saying he took a train to Poland before boarding an aircraft.

The Air Force describes the plane, a C-40B, as an “office in the sky” for senior military and government leaders, including capability to conduct secure voice and data communication.

The details of Zelensky’s travel were closely held until hours before his visit.

Biden and Zelensky confirmed the visit publicly at 1 a.m., roughly an hour before the plane took off from Poland.

Biden is slated to welcome Zelensky to the White House at 2 p.m.

Updated at 1:51 p.m.