BERLIN (Reuters) - Germany's Defence Minister Ursula von der Leyen described Donald Trump's gains in the U.S. presidential election as a "huge shock" on Wednesday and asked him for assurances on his commitment to NATO.

Von der Leyen told broadcaster ARD that the Republican candidate's strong showing was "not a vote for him but rather against Washington, against the establishment".

"It was a big shock when I saw the way things are heading," she said as Trump edged closer to winning the White House with a series of shocking wins in key states such as Florida and Ohio, rattling world markets.

Germany, like other European countries, was alarmed by Trump's comments earlier in the campaign that if Russia attacked a NATO member, he would consider whether the targeted country had met its defense commitments before providing military aid.

"Of course we Europeans, as a NATO ally, know that if Donald Trump becomes president, he'll ask: What are you contributing to this alliance?" von der Leyen, a member of Chancellor Angela Merkel's conservatives, said.

"But we're also wondering, what's your position on this alliance?" she added, in the first comments from a German minister on the U.S. vote.

Von der Leyen said the German government now needed to find out know who their contact person would be in a Trump government and what campaign announcements he wanted to implement.

"There are many questions yet to be answered," she said.

Regarding Trump's pledge to "Make America Great Again", von der Leyen said that would only be possible with a strong economy and that, in turn, would only be possible if he did not create uncertainty.

"It's in our interest that the America remains prepared to take on responsibility and open to the world," she said.

(Reporting by Andreas Rinke; Writing by Michelle Martin; Editing by Christian Schmollinger and Andrew Heavens)