In his ongoing effort to negotiate an end to the war in Ukraine, President Donald Trump has not ruled out the deployment of U.S. troops on the ground in Europe, according to a senior Trump administration official.

“I don’t think there's a red line,” the official told Politico. “So I think it just kind of remains to be seen. [President Trump] would like the Europeans to step up.”

The official’s comments come in the wake of Trump’s high-stakes meeting with Ukrainian President Volodymyr Zelenskyy on Monday — an event that was seen as a major improvement over the two’s previous get-together in February that was labeled by many critics as a disaster. Trump met with Russian President Vladimir Putin in Alaska on Friday, and is now attempting to arrange a trilateral summit with both leaders in the hopes of ending the ongoing Russo-Ukraine War.

Trump has been vague in what concessions he’d be willing to make to see an end to the war, having sparked fear among some European leaders that he may ask Ukraine to cede a significant share of its territory and leave the Eastern European nation without any sufficient security guarantees.

According to the official, however, Trump apparently seems open not only to push for major security guarantees for Ukraine, but is even considering the deployment of U.S. troops in Europe to enforce those potential security guarantees.

“I think if the last piece of the puzzle was for a period of time to be a part of a peacekeeping force, I think he would do it,” the official said.

This comes as a reversal from Trump’s position back in February, when he explicitly ruled out the idea of there being any U.S. military presence in Ukraine. On Monday, Trump hinted that he may be open to American troops being deployed in a vague statement that the United States would provide “a lot of help when it comes to security."

Having been waged since 2014, and escalated in 2022 with Russia’s invasion of Ukraine, the Russo-Ukraine War has seen

more than one million casualties

as of June.