WASHINGTON (Reuters) - NATO's mutual defense guarantee is a commitment that comes without any "conditions or caveats," British Defence Secretary Michael Fallon said on Thursday.

"It is an absolute commitment that we help each other if any one member of NATO is attacked," Fallon said in Washington.

Republican U.S. presidential nominee Donald Trump told the New York Times that if he is elected, he might abandon NATO's guarantee that any member, including the United States, would defend the others if they were attacked, or Article 5.

Trump said that Washington would only come to the aid of other members if they had "fulfilled their obligations to us."

However, Fallon said that member states were increasingly accepting their responsibilities and the North Atlantic Treaty Organization was an important alliance given a resurgent Russia.

"We've seen a growing solidarity and unity about the alliance now," Fallon added.

(Reporting by Idrees Ali; Editing by James Dalgleish)