David Jackson

USA TODAY

TAORMINA, Italy — Wrapping up his first foreign trip as commander-in-chief, President Trump left the G-7 summit Saturday amid ongoing international deadlocks over trade, climate change and the fate of a global treaty on restricting heat-trapping carbon emissions.

While the American president and G-7 allies agreed to increase efforts to fight terrorism, Trump, his aides and other world leaders acknowledged ongoing disputes over trade rules and whether the United States should remain part of the Paris climate change agreement.

Climate talks in particular were "very unsatisfactory," German Chancellor Angela Merkel told reporters.

Trump, who received conflicting advice on climate change from aides, tweeted after the G-7 meetings that "I will make my final decision on the Paris Accord next week!" The precise date is uncertain, and he has delayed previous plans to make that announcement.

Speaking later to U.S. military personnel before heading back to Washington, Trump said many countries have "a large number of disagreements" with the U.S., but he believes he hit "a home run" during his trip.

"We made a lot of good friends this week," Trump said.

His voyage began in the Middle East, continued to the Vatican for a meeting with Pope Francis, led to NATO headquarters in Brussels and wound up on the Sicilian coast for the Group of Seven industrial nations summit.

Trump took to Twitter to say that "lots of very important matters" were discussed at the G-7, but "first on the list, of course, is terrorism."

He also cited pledges by members of the North Atlantic Treaty Organization to "step up payments considerably, as they should," on their defense budgets. While some analysts criticized Trump for not endorsing the alliance's mutual defense pledge, the president tweeted that "money is beginning to pour in - NATO will be much stronger."

In addition to protesting Trump's views on climate change, Germany and other G-7 members pushed back on Trump's claims that other countries engage in unfair trade practices against the United States. The back-and-forth ended what European Union President Donald Tusk called "the most challenging G-7 summit in years."

Hanging over the president's entire trip: Ongoing investigations back home of any links between Trump's campaign last year and Russians who sought to influence the presidential election by hacking Democrats. Trump and his aides have denied collusion and described the investigations as "witch hunts."

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While other leaders held traditional post-G-7 news conferences Saturday, Trump did not. Instead, he spoke to U.S. military personnel at the nearby Naval Air Station Sigonella, from which Air Force One departed.

The president and first lady arrived at Andrews Air Force Base, Md., Saturday night and returned to the White House aboard Marine One, landing on the South Lawn at 9:22 p.m. The president waved as he entered the residence but made no comment.

Trump focused on terrorism, NATO

Recounting his trip, Trump stressed the need to win the fight against terrorism. Citing this week's attacks in the United Kingdom and Egypt, Trump said the U.S. is resolved to defeat terrorism, which he called "a bad threat to all humanity."

In the Middle East, a more conciliatory Trump praised prospects for new peace talks and urged Muslim leaders to help defeat terrorism; during a more combative visit to Brussels, Trump demanded changes to the U.S. financial relationship with NATO. Both visits drew some criticisms.

During the president's sojourn through Saudi Arabia, Israel and the Palestinian Authority, analyst Aaron David Miller — a Middle East negotiator in both Republican and Democratic administrations — said his head "was spinning" over Trump's hopes for a peace deal.

"Never has a US President expressed so much confidence in a conflict-ending peace agreement w/so little prospect of success," tweeted Miller, vice president with the Woodrow Wilson International Center for Scholars.

In Brussels, Trump surprised NATO leaders by avoiding an explicit endorsement of "Article 5," the mutual defense provision of the NATO charter that requires members to regard an attack on one member as an attack on all.

"The President chose instead to alienate our European and Canadian allies by publicly berating them over their defense spending," said Kori Schake, a former National Security Council official and now a research fellow at the Hoover Institution at Stanford University. "He's just made it an awful lot easier for allies to refuse anything he ever needs from them."

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Aides said Trump fully supports NATO, noting that he spoke at a memorial dedicated to invocation of Article 5 after the 9/11 terrorist attacks in 2001. "It's clear that the president is committed to Article 5 and the alliance," National Security Adviser H.R. McMaster said. "That's why he was there for the leaders' meeting."

During his speech in Brussels, Trump also demanded NATO members increase defense spending, arguing that the United States is carrying too much of the financial burden. He echoed those comments to the troops at Naval Air Station Sigonella, saying "other nations must pay more" for common defense. "We're behind NATO all the way," the president said, "but we want to be treated fairly."

Despite Trump's suggestions to the contrary, NATO countries do not owe money to the United States; alliance members have agreed to increase their own defense spending to 2% of gross domestic product, and say they are making progress toward that goal.

Trip ends without final decision on Paris Accord

At the G-7, held at a hilly seaside village, the issues of terrorism, trade and climate change dominated meetings mostly closed to the press.

European officials have long sought to pressure Trump to stay in the Paris agreement. During their meeting at the Vatican, Pope Francis gave Trump a book he wrote on climate change.

In backing the pact reached in Paris in 2015, supporters say countries should be required to reduce carbon emissions as to way to mitigate the threats of global warming.

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While some Trump aides want the U.S. to stay in the Paris framework, other officials say new regulations will hurt the American energy industry, thereby reducing economic growth.

The G-7 was unable to come to a consensus on the topic. The annual G-7 communique — shorter than usual at only six pages — said that nearly all the members agree on climate change, with one exception: "The United States of America is in the process of reviewing its policies on climate change and on the Paris Agreement and thus is not in a position to join the consensus on these topics."

Gary Cohn, director of Trump's National Economic Council, said Trump's views on climate change are "evolving" and that he came to the G-7 "to learn and get smarter" ahead of his decision on the Paris deal. "His basis for decision ultimately will be what's best for the United States," he said.

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In terms of trade, Trump reportedly criticized the Germans as "very bad" on the process, and made other complaints about the global trading system during G-7 meetings. Other countries said they are following mutually agreed upon rules. Merkel pointed out that her country couldn't re-negotiate rules with the United States if it wanted to, as Germany is a member of the European Union.

"We have a currency union," Merkel told reporters. "We are practically a common market. To pick out one country is, I think, not so appropriate."

Awkward moments along the way

Aides said Trump advanced his agenda and made new connections with world leaders during the trip, though it also had its share of awkward moments.

There was a long and seemingly competitive handshake between Trump and new French President Emmanuel Macron. There was Trump pushing aside the prime minister of Montenegro to get to the front of a NATO family photo. British Prime Minister Theresa May got on Trump over U.S. intelligence leaks, while Merkel pushed back against Trump complaints about car trading policy.

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At times, the body language in group settings seemed to reflect the divisions between Trump's "America First" approach and the views of other nations. At one point, as G-7 leaders strolled the ancient mountain streets of Taormina, Trump followed behind on a golf cart.

During the G-7, observers accused Trump of not using headphones to hear the translations of comments by speakers from other countries. Spokesman Sean Spicer said Trump used a different method, tweeting: "As usual @POTUS wears a single ear piece for translation in his right ear."