US President Donald Trump's unusual handshaking style has come under scrutiny yet again - this time, during an unexpected standoff with French counterpart Emmanuel Macron at the US embassy in Brussels before a Nato summit.

Mr Macron refused to be shaken. The 39-year-old tightly held Trump's notorious power grip as they sat beside each other, his mouth clenched and eyes fixed at the tycoon's squinted stare.

Their knuckles turned white as both men clenched their jaws.

Here's a look at other times world leaders have made the simple handshake an awkward affair.

Shinzo Abe and Donald Trump

This epic 19-second-long handshake with Mr Shinzo Abe at the White House in February left the Japanese Prime Minister visibly bewildered.

Justin Trudeau and Donald Trump

Mr Trump's next would-be victim, Canadian Prime Minister Justin Trudeau, was having none of it. During his visit to the White House, he cleverly neutralised the former's aggressive approach while meeting outside the White House, and later appeared to contemplate Mr Trump's proffered hand in a comical scene at the Oval Office that went viral and sparked countless memes.

Barack Obama and Raul Castro

The mother of all bungled handshakes unfortunately belongs to the former US President, after a historic meeting with Cuban leader Raul Castro in March last year.

Everything about the horribly uncoordinated handshake screamed awkward - from Mr Castro's forceful armgrab to Mr Obama's limp hand.

Vladimir Putin and Barack Obama

Russia-US ties took another hit when Mr Obama and Russian President Vladimir Putin - not exactly the best of pals - were caught in an awkward handshake moment during a bilateral meeting at the United Nations' New York headquarters in September 2015.

Mr Obama proffers his hand, but Mr Putin stares at it and holds back his own. Super awkward.

Francois Hollande and John Kerry

Mr Kerry, who was US Secretary of State then, was visiting the French President at the Elysee Palace in January 2015.

Cue comic relief as Mr Kerry fended off Mr Hollande's une bise (a traditional French greeting of a kiss on the cheek) attempt with outstretched arms, before the fumbling pair came together in an uncomfortable embrace.

Xi Jinping and Shinzo Abe

Meeting for the first time since they took office, Mr Abe was treated to a frosty reception by the Chinese President at the Asia-Pacific Economic Cooperation Summit in November 2014.

An image of a stiff and unsmiling Mr Xi greeting Mr Abe at Beijing's Great Hall of the People before clasping hands drew a whirlwind of speculation over how their meeting panned out.

Barack Obama, Tony Abbott and Shinzo Abe

A weird three-way handshake grabbed the headlines at the G20 Summit in Brisbane in November 2014.

Mr Abe and then-Australian Prime Minister Tony Abbott were sharing a handshake when the former waved Mr Obama over, resulting in what the Guardian described as a cheerful-looking "chorus line".