TAORMINA, Italy (AP) -- In the Middle East, President Donald Trump was feted with pageantry, the leaders of Saudi Arabia and Israel seemingly in competition to outdo the other with the warmth of their welcomes and the depth of their pledges of cooperation.
But in Europe, Trump has faced a far cooler reception and has been eager to go on the offensive.
Cajoled on issues like climate change and NATO's defense pact, he's responded by scolding some of the United States' most loyal allies for not paying their fair share. He's also refused to explicitly back the mutual defense agreement that has been activated only once, during the darkest hours of September 2001.
Still, Trump hailed the trip a success as he arrived to the G-7 summit in Sicily Friday, the final stop of his maiden international trip, a grueling nine-day, five-stop marathon.
"Getting ready to engage G7 leaders on many issues including economic growth, terrorism, and security," Trump wrote on Twitter. "Trip has been very successful. We made and saved the USA many billions of dollars and millions of jobs."
Once more, he will likely be received warily, a president who ran on a campaign of "America First" with suggestions of disentangling the United States from international pacts, now engaged in two days of pomp and policy with the leaders of the United Kingdom, France, Germany, Italy, Japan and Canada.
"There is no doubt that this will be the most challenging G-7 summit in years," said Donald Tusk, president of the European Council.
He said the group's leaders "sometimes have very different views" on topics such as climate change and trade, "but our role as the EU is to do everything to maintain the unity of the G-7 on all fronts. Most importantly unity needs to be maintained when it comes to defending rule-based international order."
The White House believes that Trump has made personal breakthroughs with his peers, having now met one-on-one with all the leaders of G-7.
"It's time for him to have an intimate discussion and understand their issues but, more importantly, for them to understand our issues," national economic adviser Gary Cohn told reporters on Air Force One late Thursday.
One of those relationships was on display as Trump began the day with a meeting with Japanese Prime Minister Shinzo Abe. The president hosted Abe at the White House and his Mar-a-Lago resort back in February, where they appeared to hit it off.
Abe was the latest world leader to publicly flatter Trump, saluting his visit to the Middle East and address to NATO on Thursday.
"Unfortunately," Abe told reporters, "this time around we won't be able to play golf together."
The president said he and Abe would cover many topics, including North Korea, which he said "is very much on our minds."
"It's a big problem, it's a world problem, but it will be solved at some point. It will be solved, you can bet on that," Trump said. North Korea has conducted a series of recent missile tests, rattling its Pacific neighbors.
Foreign policy will be the focus on Friday, with meetings on Syria, Libya, North Korea, Afghanistan and Pakistan. Other meetings over the two days will include discussions of global economy and climate, a meeting with small African nations --- Trump will be seated between the leaders of Niger and Tunisia --- and migration issues.
Trade will also be a big topic, with Cohn saying the United States' guiding principle will be "we will treat you the way you treat us," suggesting that retaliatory tariffs could be imposed.
The day will feature a welcoming ceremony and concert at the remains of an ancient Greek temple, as well as a relentless number of meetings, many of which White House aides are hoping to keep short in order to keep Trump's attention. What the Sicily stay will likely not offer: a news conference, as Trump appears set to defy presidential tradition and not hold one during the entire trip.
The Republican president arrived in Italy fresh off delivering an unprecedented, personal rebuke to NATO, traveling to its gleaming new Brussels headquarters to lecture its leaders to their faces on the need for them to spend more on defense.
"This is not fair to the people and taxpayers of the United States," Trump said. "If NATO countries made their full and complete contributions, then NATO would be even stronger than it is today, especially from the threat of terrorism."
The 28 member nations, plus soon-to-join Montenegro, will renew an old vow to move toward spending 2 percent of their gross domestic product on defense by 2024. Only five members meet the target: Britain, Estonia, debt-laden Greece, Poland and the United States, which spends more on defense than all the other allies combined.
Trump refused to say he would adhere to the mutual defense pact, known as Article V, though the White House later claimed that his very presence alongside twisted World Trade Center steel --- a memorial outside NATO headquarters --- was evidence enough of his commitment.
As Trump spoke, the NATO leaders, including German Chancellor Angela Merkel and French President Emmanuel Marcon, stood in awkward silence. Later, as they took the traditional "family photo" group shot, the heads of state quietly kept their distance from Trump, who minutes earlier was caught on video appearing to push the prime minister of Montenegro out of the way to get to his spot.
The president's remarkable public scolding of NATO came amid a backdrop of uncertainty in Brussels toward Trump over his past comments publicly cheering the United Kingdom's vote to leave the EU last summer and slamming the alliance during his transition as "a vehicle for Germany."
But while Trump lectured some of the United States' strongest allies, he cozied up to the repressive regime in Saudi Arabia while pushing for the Arab world to root out extremism at home. He made deals for more than $100 billion in military equipment, christened a hurriedly finished counter-terrorism center, and was the guest of honor at a number of lavish welcoming ceremonies, one complete with a sword dance.
It was a similar story in Israel, where Prime Minister Benjamin Netanyahu warmly greeted Trump and the president reciprocated with emotional appearances at the Western Wall and Holocaust museum and suggested that there was an opening for peace with the Palestinians.