The pivotal meeting is scheduled for Friday, taking place in Alaska, where Donald Trump and Vladimir Putin will closely observe each other for any sign of vulnerability.

The situation is precarious, with Trump pressing Putin for an immediate truce in Ukraine, two U.S. nuclear submarines advancing towards Russia, and daunting warnings about catastrophic weapons emerging from Moscow.

As they encounter each other in person for the first time since 2019, the demeanor of both men will be key as they try to gain the upper hand.

Body language expert Judi James, who has analyzed their earlier encounters, suggests that humor might be Trump’s key tactic to undermine and challenge Putin.

‘Putin seems more than comfortable being on the receiving end of frosty greetings,’ she told the Daily Mail.

Trump and Putin met six times during the U.S. President’s first term.

Initially, Trump appeared successful in recruiting Putin into a kind of ‘global alpha men’s club,’ James said.

But, more recently, Putin has ditched their ‘bromance,’ leaving Trump disappointed and frustrated.

‘Trump’s meetings with Putin work at a visceral level rather than an intellectual one,’ James said.

‘Their interactions have been a classic display of alpha versus alpha, with Trump showcasing strength and power to gain mutual respect from Putin.’

‘However, despite this, Putin is highly astute regarding body language. He has effectively bypassed the unwritten alpha agreement, and it will be intriguing to observe how Trump confronts him directly in their engagement.’

Here is an analysis of some of their previous key encounters, and what their body language tells us about the inner workings of their relationship.

2017:  G20 summit in Hamburg, Germany

It was an awkward start when the two leaders held their first meeting on the sidelines of the G20 summit.

‘They appeared to put in considerable effort to look distant and out of sorts with each other,’ said James.

‘Trump sat on the edge of his seat, his head slumped, making the back of his jacket ripple up like a wave behind his neck.’

But Trump went on to use two key ‘power moves’ on Putin.

Initially, he acted as if disinterested in his counterpart, blinking and diverting his gaze around the room, deliberately avoiding eye contact with the Russian leader.

Second, Trump shot out his arm to perform a ‘hand platter’ shake, with his palm facing up.

That forced Putin to lean across and put his hand on top of Trump’s, with the US. President gripping it and determining the length of the handshake.

Putin adopted a ‘vaguely compliant air’ during the formal photographs, looking down with a ‘miserable expression.’

Trump repeated the ‘hand platter’ shake to show who was in charge.

2018: Helsinki

The two men held two hours of talks behind closed doors.

At a joint press conference President Trump then contradicted his own intelligence agencies, suggesting there was ‘no reason’ why Russia would have interfered in the 2016 U.S. election.

‘By now Trump and Putin seemed to have had a meeting of alpha minds, with their choreographed, mirrored poses suggested like-minded thinking,’ James said.

‘They both stood with their chests puffed like Marvel superheroes, it looked like the perfect alpha pairing.’

However, there was then a ‘dramatic mood change’ from Putin.

‘It was noticeable that Putin’s poses of relaxed and open confidence had vanished,” James said.

Trump this time offered a normal handshake with his palm turned inward.

But when they shook, there was a ‘look of wary eye-to-eye confrontation’ suggesting a ‘complex truce.’

James said: ‘They glared like boxers before a fight and both performed a lip-clamp to suggest firmness and resolution.

‘The grasp looked tight, with Trump’s knuckles going white and, importantly, Putin’s left hand remain curled round his chair arm, suggesting he had no intention of being rocked off balance by one of Trump’s jerking, yanking power shakes.’

When Putin gave Trump a soccer ball as a gift, the U.S president held it ‘stiffly’ before throwing it to Melania.

2019: Osaka

When Trump and Putin last met in person in Osaka, Japan in 2019, their ‘bromance’ was still superficially on track.

Putin walked into the room and Trump threw both arms out to ‘signal he felt he was greeting an old friend,’ said James.

‘There was a lack of fundamental mirroring here though,’ she added. ‘Putin’s back was ramrod straight while Trump looked less formal.’

Once again, Trump’s handshake was telling.

He extended his hand for a tight clasp and then performed a ‘shake and yank,’ attempting to pull Putin towards him to establish control.

However Putin did not budge.

‘There was smiling on both sides though to register an established friendship,’ said James.

‘Putin showed he could joke with Trump in English, and Trump performed preening gestures to suggest he was enjoying trading jokes with a fellow alpha.

‘Trump’s body language tactics tend to be basic and earthy. He is a great power-player with his power pats and power shakes.’

But such rituals that ‘seem so important to Trump seem to mean very little to Putin long-term,’ she said.