Polish Prime Minister Donald Tusk has confirmed that, in the event of another Russian attack on Ukraine, the United States will respond militarily. Tusk made the remarks following the Berlin summit on Ukrainian peace, highlighting that for the first time, American negotiators, including Steve Witkoff, were unequivocal about Washington’s willingness to provide direct military support if Russian forces violate a ceasefire.

Tusk noted that this clear commitment underscores a united front among the United States, European nations, and Ukraine. “Perhaps for the first time it was so clearly visible that the Americans, Europeans and Ukraine are all on the same side,” he said. He added that the West must act in unison to compel Moscow to engage in serious negotiations or agree to a ceasefire, warning that divided actions would only allow Russia and President Vladimir Putin to exploit differences among allies.

The statements come after Ukrainian President Volodymyr Zelenskyy met European leaders in Berlin on December 15. Earlier on the same day, Ukrainian and U.S. delegations discussed a proposed peace plan. During those talks, U.S. negotiators, including Witkoff and Jared Kushner, reportedly pressed Kyiv to consider ceding parts of Donbas still under Ukrainian control. Zelenskyy, however, reiterated Ukraine’s firm stance, stressing that the country will not recognise Donbas as Russian, either de facto or de jure.

Tusk emphasised that acting in solidarity with the United States and Ukraine is the only effective way to signal to Russia that attempts to divide the West will fail. The Polish prime minister framed this approach as essential for forcing meaningful negotiations toward ending the war or achieving a stable ceasefire.

The Berlin discussions and subsequent comments reflect an intensified Western effort to coordinate security guarantees for Ukraine while maintaining Kyiv’s territorial integrity. These developments also underline the growing role of the U.S. in providing direct military assurances to deter further Russian aggression.