Melania and Donald Trump with Polish President Andrzej and Agata Kornhauser-Duda at a ceremony.

President Donald Trump said on Thursday the United States had demonstrated its commitment to NATO's defense through words and actions, and called on Russia to end its "destabilising" action in Ukraine and elsewhere in the world. Trump's reference to Article Five of the NATO treaty, which guarantees that alliance members will defend each other, represented a change of tone from the president, who upset allies by not mentioning support for the provision during a trip to NATO headquarters in May. However, he again touched upon the subject of meeting obligations and said, "We are grateful for the example Poland has set by being one of the few nations that actually meets its (NATO's) financial obligations."