Ukraine's President Volodymyr Zelensky will meet US leader Joe Biden and address Congress in Washington on Wednesday, a visit the White House said will send Russia a strong message of Western unity. The visit will "underscore the United States' steadfast commitment to supporting Ukraine for as long as it takes," White House spokeswoman Karine Jean-Pierre said in a statement. It will be Zelensky's first trip outside Ukraine since Russian forces invaded in February, when they planned for a rapid takeover of Kyiv and much of the country. "On my way to the US to strengthen resilience and defense capabilities of (Ukraine)," Zelensky tweeted, also confirming that he will make a speech to Congress. Zelensky will visit the White House where Biden is to announce a new arms package worth almost $2 billion that a senior administration official said includes Patriot air defense missiles. Patriot missiles are seen as crucial to help Kyiv fend off Russia's punishing missile and drone attacks on its infrastructure. Zelensky is then expected to address a joint session of Congress, which House Speaker Nancy Pelosi said would be "a very special focus on democracy." President since 2019, Zelensky has made it a point of his leadership to stay in his battered country, close to the people and soldiers fighting in a war that Ukraine and its allies call an unprovoked Russian aggression. His wife, Olena Zelenska, travelled to Washington in July to address Congress and has made several other international trips pleading for Ukraine, as have his aides and ministers. The visit to the US was quietly planned, beginning with a phone call between Biden and Zelensky on December 11, followed by a formal invitation one week ago and confirmation of the visit on Sunday. Details of the visit leaked on Tuesday afternoon, with officials stressing to US media that there were still security concerns over Zelensky's travel. In White House talks, Biden and Zelensky will discuss the arms and training provided by the United States and allies, sanctions and other pressure on Russia, and economic and humanitarian aid that Ukraine needs, the senior White House official said. "They will discuss every element of this conflict, including the situation on the battlefield and including the question of where the war goes from here," the official said. The visit will send Putin "a strong message of unity and resolve from the White House, from Washington, from the free world, on behalf of all the nations supporting Ukraine," the official added. But that does not include pressuring Zelensky into talks with Putin, the official stressed. On Tuesday, Zelensky had made a surprise visit to the eastern front-line city of Bakhmut, a site of some of the fiercest fighting in the war, his office said, where, dressed in trademark combat khaki, he handed out medals to soldiers.