Elon Musk was seen making a series of bizarre faces during a photo-op with Apple CEO Tim Cook today during a state banquet in China. 

Musk and Cook are among the dozens of top business leaders who have travelled with Donald Trump to China this week. 

The US president is in Beijing to develop his nation's relationship with Xi Jinping, the leader of China. 

But despite the gravity of the meeting, tech billionaire Musk tried to inject a bit of levity to the state banquet dinner held in China's capital. 

He was seen sat down at a table, with Apple's leader Tim Cook stood just behind him. 

The pair were posing for a photo with a third, unknown man. But while Cook was seen smiling at the camera, Musk decided to pull a series of quirky faces. 

He could also be seen grinning as he put two thumbs up. 

But Musk's cheeriness was not matched by Cook, who dropped his smile as soon as he began walking away from the photo-op. 

Earlier, Musk was seen hand-in-hand with his son X Æ A-12, having taken him to an important meeting with China's leadership. 

The boy, born to Musk and his then-girlfriend Grimes in 2020, was seen wearing a blue vest that appeared to have taken inspiration from Chinese culture over a white shirt. 

He was also seen carrying what appeared to be a bag in the shape of a Chinese dragon mask. 

The pair were seen today walking through the Great Hall of the People, a government building. 

Musk's antics come as Xi Jinping and Donald Trump started a crucial series of meetings in Beijing on Thursday in a US-China summit where stability in the relationship is the main goal of the two days of discussions.

The White House and Chinese state media said the leaders concluded their meeting Thursday morning after about two hours. 

Trump is expected to leave just after midday Friday after a final private meeting with Xi. But few breakthroughs are expected on divisive issues ranging from the Iran war, trade, technology and Taiwan.

Trump hopes to focus the summit talks on trade and deals for China to buy more agricultural products and passenger planes, setting up a board to address their differences and avoid a repeat of the trade war ignited last year after Trump's tariff hikes.

In their closed-door meeting, Xi told Trump that if Taiwan is handled well, US-China relations 'will enjoy overall stability.' If not, the two countries risk 'clashes and even conflicts, putting the entire relationship in great jeopardy,' Xi said, according to China's official Xinhua News Agency.

Trump in December authorized an $11 billion arms package for Taiwan, a self-governed island that Beijing claims as its own territory. The US has not yet moved forward with delivery.

Xi said China's door of opening to US business will only open wider, he told American corporate leaders who accompanied Trump. The US president said the business leaders all respect and value China and he encourages them to expand cooperation with China, Xinhua reported.

The war with Iran is also likely to be a key topic. Ahead of the meetings, Trump hoped China would use its considerable leverage to prod Iran to agree to US terms to end the ongoing war or reopen the critical Strait of Hormuz, but he has tempered those calls ahead of the summit.