WASHINGTON — President Trump came face-to-face Friday with a putative rival for global leadership, German Chancellor Angela Merkel.

The chancellor arrived at the White House after months of back-and-forth with the new president, including Trump's claims that Merkel is "ruining" Germany by letting in too many refugees and that Germany is using the European Union as a "vehicle" for its own economic ambitions.

Merkel, meanwhile, has questioned Trump over his criticism of the EU, NATO, free-trade agreements and other multi-national agreements. Before leaving for the United States, Merkel said she would be representing Europe as well as Germany in her meeting with Trump.

"I will of course point out that for us, our country and our membership in the European Union are two sides of the same coin," Merkel told reporters.

The two leaders had little to say during a brief photo opportunity in the Oval Office.

"We talked about lots of things," Trump told reporters.

Trump and aides have sounded more conciliatory notes ahead of a summit initially scheduled for Tuesday but postponed due to a snowstorm.

The president greeted the chancellor at the door of the West Wing after her motorcade pulled up.

"The president and the chancellor have a series of meetings, and then will host a round table focusing on the importance of vocational training with both American and German business leaders," said White House spokesman Sean Spicer.

The two leaders are also scheduled to conduct a brief news conference. One possible question: Trump's unproven claim that predecessor Barack Obama had him wiretapped in the runup to last year's presidential election.

The Friday summit between the voluble Trump and the more low-key Merkel comes amid major strains in the United States-European alliance that has prevailed for decades.

While Trump and aides have expressed support for the trans-Atlantic alliance since he took office in January, the president's tart comments during last year's campaign hang over his dealings with Europe, particularly Germany.

Promoting what he called an "America First" style of economic nationalism, Trump has demanded that Germany and other NATO countries contribute more to the military alliance.

"I think NATO is obsolete," Trump told ABC News a year ago, referring to the threat of terrorism. "NATO was done at a time you had the Soviet Union, which was obviously larger — much larger than Russia is today. I'm not saying Russia is not a threat, but we have other threats. We have the threat of terrorism."

Trump has also criticized the European Union, saying he had bad experiences with EU officials during his years as a New York-based businessman, and arguing that the union's regulations are an impediment to economic growth in general. He praised Great Britain's vote last year to "Brexit" the European Union, which he has described as more or less a subsidiary of Germany.

“You look at the European Union and it’s Germany," Trump told British lawmaker Michael Gove in a January interview for The Times of London. "Basically a vehicle for Germany. That’s why I thought the UK was so smart in getting out.”

European Union President Donald Tusk said that Trump is the "threat" to western stability.

The U.S. and Germany are also at odds over relations with Russia; Trump has taken a more supportive approach, while Merkel has accused Russian President Vladimir Putin of seeking to undermine the western alliance.

In late 2015, Trump expressed irritation when Time magazine named the Merkel its Person of the Year (Trump won the honor in 2016).

Merkel has suggested disagreement with Trump policies that include a proposed travel ban — being challenged in court — from six Muslim majority counties.

The German chancellor said close cooperation with the United States should be based on "values of democracy, freedom, respect for the rule of law and human dignity, regardless of origin, skin color, religion, gender, sexual orientation or political belief."

Before leaving for the United States, Merkel said she would emphasize the common interests of the United States and Europe in her meeting with Trump, while stressing that "Europe has decided to take more responsibility in the future, both in our own neighborhood and beyond."

Merkel has also touted global trade. After a meeting this week with German business leaders, Merkel said she would also take that message to the White House.

"Talking directly is always much better than talking about each other," she said. "That will be my motto on this visit, which I am looking forward to."