U.S. President Donald Trump assured that American troops would not be deployed to defend Ukraine against Russia, clarifying remarks from the previous day that suggested the option had not been ruled out.

In a morning interview, Trump declared that Ukraine’s ambitions of joining NATO and reclaiming Crimea from Russia were “impossible.”

The day before, Trump, Ukrainian President Volodymyr Zelenskyy, and several European leaders met for extended talks at the White House, aiming to find a path toward ending the conflict with Russia. During that discussion, Trump left open the possibility of U.S. involvement in a European-led security arrangement for Ukraine, which Zelenskyy has been seeking.

Following his recent meeting in Alaska with Russian President Vladimir Putin, Trump indicated that Putin appeared receptive to certain security guarantees for Ukraine.

However, pressed during Tuesday’s appearance on Fox News’ Fox & Friends about whether American forces could be committed to defending Ukraine’s borders, Trump responded, “You have my assurance, and I’m president.” His authority over the U.S. military, however, ends with his term in January 2029.

Trump also expressed optimism about reaching a deal to halt Russia’s invasion but stressed that Ukraine would need to abandon two goals: recovering Crimea—seized by Russia in 2014—and securing NATO membership. “Both of those things are impossible,” he said.

Putin, for his part, has tied any potential withdrawal of Russian troops to Ukraine relinquishing its claims over Donetsk and Luhansk and formally recognizing Crimea as part of Russia.