OSAKA, Japan – Facing a G20 summit featuring meetings with rivals like China and Russia, President Donald Trump arrived on site Thursday after bashing some longtime U.S. allies – including Japan, his summit host.

Trump used a Fox Business Network interview to hit Japan and Germany over mutual defense commitments, and later tweeted out criticism of India over new tariffs it has imposed on the United States.

"Almost all countries in this world take tremendous advantage of the United States," Trump told Fox. "It's unbelievable, OK?"

The United States is obligated by treaty to defend Japan if it is attacked, Trump complained to Fox, "but if we’re attacked, Japan doesn’t have to help us at all ... They can watch it on a Sony television.”

The criticism came a month after Trump visited Japan to meet the new emperor.

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Trump took a softer tone as he began a series of G-20 meetings on Thursday, praising U.S. allies generally even as he voiced his displeasure with certain individual countries.

"We've been very good to our allies – we work with our allies, we take care of our allies," Trump said before a working dinner with Australia Prime Minister Scott Morrison, his first stop after landing in Japan for the G20 summit.

Trump has a long list of G20 meetings set for Friday – starting with his host, Japan Prime Minister Shinzo Abe. It also includes other leaders he criticized in the run-up: Indian Prime Minister Narendra Modi, and German Chancellor Angela Merkel.

Trump sounded more upbeat about his highest profile meeting at the G-20, a Saturday session with China President Xi Jinping to discuss the revival of talks toward a new trade agreement.

Trump's schedule on Friday includes another high-profile leader, Russian President Vladimir Putin.

"So, we'll see what happens with China, with Russia, with Japan, with many countries," Trump told reporters before leaving the White House.

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U.S. lawmakers have frequently hit Trump for being friendly to autocratic leaders like Xi and Putin while being critical of democratic allies in Europe and Asia.

Trump landed Thursday night in Osaka amid heavy rain, the fallout from a nearby typhoon.

This is Trump's third foreign trip in a month's time, his second to Japan. In late May, he traveled to Tokyo to meet Japan's new emperor. Three weeks ago, Trump made a state visit to the United Kingdom and attended a service in Normandy, France, to mark the 75th anniversary of D-Day.

Those trips featured much pomp and ceremony. This one is all business.

In addition to G-20 group meetings that start Friday, Trump has one-on-one meetings with a variety of world leaders.

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The military commitment that Trump attacked stems from a treaty the U.S. signed with Japan after it became an ally in the years after World War II. Japanese leaders have consistently said it would help the U.S. any way it could if necessary.

As for Germany, Trump again said it is not spending enough on defense under a pledge it made to the North Atlantic Treaty Organization.German leaders have said their NATO commitment involves money for their own national defense, and they believe their defense budget is sufficient.

Later, while aboard Air Force One, Trump tweeted that he is looking forward to speaking with Modi so that he can protest India's decision to increase tariffs on imports from the United States.

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"This is unacceptable and the Tariffs must be withdrawn!" Trump tweeted.

While criticizing India, Trump has been known to back tariffs himself – including heavy ones on China that are at the heart of a trade war that has roiled markets and raised prices for producers and consumers worldwide.

The China trade war one of the topics of the dinner conversation with Morrison, the Australian prime minister who in recent days said the American-Chinese trade war is hurting other countries as well.

"The collateral damage is spreading," Morrison said in a speech in Sydney this week. "The impact of any further deterioration of the relationship will not be limited to these two major powers."

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Other G-20 topics include tensions with Iran and stalled negotiations with North Korea over its nuclear weapons program.

Allies want Trump to offer a plan to contain Iran, which is threatening to revive nuclear programs that could be used to make nuclear weapons.

The G-20 comes a week after Trump ordered military retaliation against Iran for shooting down a U.S. drone, then changed his mind and went with increased economic sanctions. Trump is trying to pressure Iran into making a permanent pledge not to develop nuclear weapons.

Iran, meanwhile, has said it will defend itself against U.S. aggression.

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Some allies protested Trump's decision to withdraw the United States from the 2015 Iran nuclear agreement, in which the U.S. and other countries withdrew economic sanctions on the Tehran regime as it gave up the means to make nuclear weapons.

Trump also meets Friday with Brazil President Jair Bolsonaro, who had an unusual arrival to the G-20 summit. A Brazilian airman traveling in his entourage on a back-up plane was arrested during a re-fueling stop in Seville, Spain, on charges of carrying 39 kilograms of cocaine.