BERLIN (Reuters) - French presidential candidate Emmanuel Macron said he was sure the United States under President Donald Trump would maintain close ties with the European Union but said Europe would respond if Trump acted to weaken NATO.

Emmanuel Macron (C), head of the political movement En Marche !, or Forward !, and candidate for the 2017 French presidential election visits a qualification class for refugees of German railway operator Deutsche Bahn in Berlin January 10, 2017. REUTERS/Fabrizio Bensch

Trump has called for better relations between the United States and Russia and during the presidential election campaign rattled U.S. allies, especially in eastern Europe, by saying he would consider a country’s contributions to the NATO alliance before coming to their aid.

French opinion polls show Macron, who is running as an independent in the April-May presidential election in France, is gaining on the frontrunners, conservative candidate Francois Fillon and far-right leader Marine Le Pen.

“I want to at least give the new U.S. president a chance, but the signals from Trump up to now have been going in another direction. He doesn’t rule out the dismantling of NATO,” Macron told Germany’s Funke Mediengruppe newspaper chain in an interview published on Thursday.

“I’m convinced it’s in America’s interest to cooperate with the EU. We have common values and similarly structured economies. I doubt that Trump would defend U.S. interests without working with the EU or dealing with climate change,” he said.”

Asked about Trump’s comments on NATO, Macron said: “We would react if it came to that (weakening of the alliance). But I am warning against developing premature scenarios,” he said, without elaborating.

Trump’s nominee for U.S. Secretary of State, Rex Tillerson, on Wednesday told his confirmation hearing that NATO’s mutual defence guarantee, Article 5, was “inviolable”.

Macron also said he backed expanding sanctions against Russia if there were no progress in implementing the long-stalled Minsk peace accords for eastern Ukraine, where Kiev’s forces have been battling pro-Russian separatists.

“I’m in favor of resolving the Ukraine conflict through the Minsk peace accords. If there is no progress, it would make sense to expand sanctions against Russia. At the same time, we also need continuing and demanding discussions with Moscow,” he said.

Fillon and Le Pen both support closer ties between France and Russia and have indicated they would push for the sanctions to be dropped.