What significant diplomatic engagement occurred between U.S. and Russian officials regarding Ukraine?

U.S. Secretary of State Marco Rubio met with Russian officials in Saudi Arabia to discuss ending the Ukraine conflict, with both sides agreeing to appoint high-level teams to negotiate a peace solution that would be 'enduring and acceptable to all sides.' This meeting followed a 90-minute phone call between President Trump and Vladimir Putin a week earlier, representing the first regularized contact between the U.S. and Russia in nearly three years. Notably, Ukrainian officials were absent from these talks, with President Zelensky stating his government 'will not recognize any agreement about us made without us.'