President Donald Trump is scheduled Monday afternoon to meet with Ukrainian President Volodymyr Zelensky in the Oval Office, where six months ago the two leaders engaged in a televised shouting match that threw into doubt how long the U.S. would continue its support for Ukraine against a Russia invasion.

The leaders of Germany, France, Britain and Italy are among those who flew to Washington, D.C. on short notice to attend meetings with President Trump and President Volodymyr Zelensky of Ukraine.