Four years of Trump a shock treatment for many foreign leaders

US President Donald Trump, who is seeking reelection on November 3, has regularly jolted the world with statements about other leaders that sharply deviate from long-held diplomatic protocol.

Here are some of Trump's more memorable and controversial statements.

Trump has repeatedly stunned the US political class with his warm remarks on Russian President Vladimir Putin, whom he described during his 2016 campaign as "so highly respected" around the world.

At their first official meeting in 2018 in Helsinki, Trump appeared to side with Putin over the US intelligence community's finding that Russia had interfered in the US election to support the New York tycoon.

"He just said it's not Russia," Trump said at a joint news conference. "I will tell you that President Putin was extremely strong and powerful in his denial today."

Trump has shown an affinity for authoritarian-minded rulers while clashing with fellow leaders of liberal democracies.

In an interview with investigative reporter Bob Woodward for his book "Rage," Trump voiced fondness for Turkish President Recep Tayyip Erdogan even though he said everyone had warned him, "'What a horrible guy.'"

"It's funny, the relationships I have -- the tougher and meaner they are, the better I get along with them," he said.

Also speaking to Woodward, Trump said of Saudi Crown Prince Mohammed bin Salman, "I saved his ass" after the kingdom came under fire for killing US-based dissident writer Jamal Khashoggi.

And in a 2019 meeting with Egypt's general-turned-president, Abdel Fattah al-Sisi, Trump raised eyebrows by welcoming him with the greeting, "Where's my favorite dictator?", according to The Wall Street Journal.

Trump has caused a sense of rhetorical whiplash over North Korean leader Kim Jong Un, considered by human rights groups to be one of the world's most brutal dictators.

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In 2017, Trump threatened on Twitter to launch "fire and fury" against North Korea and mocked the young leader as "Little Rocket Man."

But after a made-for-television summit in 2018, the first ever between US and North Korean leaders, Trump changed his tune and appeared smitten by Kim's flattering tone.

"We fell in love, OK? No, really -- he wrote me beautiful letters," Trump told a rally.

Trump's comments have gone in the other direction over Chinese President Xi Jinping, whom he had been careful not to criticize personally.

After Covid-19 emerged in China, Trump tweeted in February that Xi was "strong, sharp and powerfully focused" and predicted a "very successful operation" to contain the disease.

But as coronavirus deaths in the United States soared to a global high and became a major campaign issue, Trump in May accused China of spreading "pain and carnage."

"It all comes from the top," he tweeted. "They could have easily stopped the plague but they didn't!"

Some of Trump's most stinging attacks have been not on adversaries but on allies.

Trump has repeatedly lashed out at German Chancellor Angela Merkel for welcoming refugees, incorrectly tweeting in 2018 that crime had soared and that Germans "are turning against their leadership."

After a summit in Canada, Trump tweeted that Prime Minister Justin Trudeau was "very dishonest & weak" over a dispute on US tariffs.

Trump has also publicly criticized French President Emmanuel Macron and former British prime minister Theresa May after they distanced themselves from his nationalist rhetoric.

Some of Trump's most vicious comments have been directed at London Mayor Sadiq Khan, who is Muslim, with the US president calling him a "stone cold loser."

While foreign leaders generally brush off Trump's words, his jabs have occasionally caused real anxiety.

In one Fox News interview, Trump called the people of Montenegro "very aggressive," undermining security assurances to the former Yugoslav republic that had recently joined the NATO alliance after a coup plot allegedly backed by Russia.