United States Secretary of State Marco Rubio has called on Russia and Ukraine to submit clear and actionable proposals for ending their conflict, warning that Washington may step back from its mediating role if no progress is made. During a press briefing on Tuesday, U.S. State Department spokesperson Tammy Bruce shared Rubio’s message, emphasizing the urgency of the moment.

“We are now at a time when concrete proposals need to be delivered by the two parties on how to end this conflict. How we proceed from here is a decision that belongs now to the president,” Rubio stated, referring to President Donald Trump. He noted that if the situation does not improve soon, the United States will consider withdrawing as a mediator.

Rubio had earlier signaled that this week would be critical in determining the future of U.S. involvement in negotiations between Moscow and Kyiv. However, he did not set a specific deadline for when the administration’s stance might shift, leaving the diplomatic window partially open but under pressure.

In addition to addressing the Eastern European conflict, Rubio met on Tuesday with Bulgarian Foreign Minister Georg Georgiev to discuss a range of bilateral and regional security topics. According to a separate readout from the U.S. State Department, the two leaders focused on strengthening bilateral defense cooperation and enhancing joint energy strategies.

Topics discussed included Bulgaria's acquisition of its first F-16 fighter jets and the importance of energy diversification in the region. The officials also emphasized the need for robust investment screening mechanisms to protect Bulgaria and NATO infrastructure from external threats.

The meetings underscore the increasing importance of Central and Eastern Europe in U.S. foreign policy, as Washington continues to balance its commitments to allies while urging conflicting parties to take responsibility for diplomatic resolutions.

With the conflict between Russia and Ukraine still unresolved and geopolitical tensions rising, Rubio’s message signals a potential shift in U.S. posture if diplomacy fails to produce measurable progress. The next steps now lie with President Trump, who will weigh the future of American involvement based on developments in the coming days.