President Donald Trump and Russian leader Vladimir Putin “looked like buddies” during their initial greetings on the tarmac in Anchorage, Alaska — but by the end of their historic summit the dynamic had shifted.

“Trump stood facing toward Putin and clapped for him as he approached, and symbolically, as the host, that’s typically celebratory,” body language expert Patti Wood told The Post about the moment Putin, 72, initially approached Trump, 79, at the Joint Base Elmendorf-Richardson. 

Wearing a big grin, Trump appeared “positive and confident” leading up to their first handshake, which “communicated that Trump had positive expectations for the meeting,” Wood said. 

When their hands met, however, “a little battle” broke out between the world leaders. 

“When they get into the handshake, Trump is on the bottom and Putin is on top…Trump pulled Putin’s arm in, held it close to his body.

“Typically, Trump pulls the other person’s hand close to his body to say, ‘I win. I win the war,’” she said. “And then he patted Putin’s arm with his left hand…that pat on the arm says, ‘Let go, I’m winning.’”

But Putin played along, echoing the gesture. 

“Putin patted Trump on his left shoulder, Trump patted him again – so they were using their hands to hit each other. There was a little power battle going on,” Wood said. 

By the end of the lengthy handshake, “you see them walking side-by-side and they look like buddies,” according to Wood. 

On Friday, another body language expert, Dr. Beth Dawson, told The Post that the leaders’ nonverbal behaviors during the greeting indicated a friendly, “genuine connection” between them.

But after three hours of unsuccessful talks about ending Moscow’s war on Ukraine, Trump was less enthused as the two leaders appeared at a news conference and declined to answer questions.

“During the first handshake, Trump had the palm up, but during the last one, he’s doing what I call a ‘slice’ handshake – his hand goes out sideways, his fingers are not cupped, they’re sharp…it’s very abbreviated. And the expression on Trump’s face is weariness – his body language is weary and tired,” Wood said. 

“Typically when men shake hands, they face each other to show their strength and bravery and openness. Trump is sideways rather than facing Putin, and that’s his desire to escape and get away,” Wood explained. 

Putin, meanwhile, leaned backward and sported a “little kid grin” during their farewell, according to Wood.