Donald Trump has managed to send a tweet from China – a country that bans Twitter and other foreign social networks.
The US President addressed his latest message at about 6am UK time to his host, President Xi Jinping.
Mr Trump wrote: “President Xi, thank you for such an incredible welcome ceremony. It was a truly memorable and impressive display!”
He included a clip from ABC News of the ceremonial reception he received outside the Great Hall of the People and a link to an Instagram gallery with more photos.
The President also changed his Twitter banner to a picture of him and President Xi and their wives Melania and Peng Liyuan surrounded by Chinese opera performers.
There was much speculation before the visit to the third country on Mr Trump’s 11-day Asian tour about whether he would use Twitter.
Some wondered if he may stay off his primary medium for addressing his supporters out of respect for China’s domestic ban.
But the tweet prompted much discussion on China’s state-sanctioned social media sites, like Weibo, with many asking how he was able to do something forbidden for Chinese citizens.
“I guess he must have done it via wifi on a satellite network,” said one user.
Many foreigners and overseas visitors attempt to get around the ban by using a virtual private network (VPN), which can sidestep the controls the Chinese authorities impose on the web.
Without one, anyone attempting to access banned sites through China’s own networks finds their attempt instantly blocked.
But VPNs are heavily frowned upon in China, with a large department tasked with blocking access to most and laws in place that enable the authorities to arrest or fine those who use them and host them, according to the Cloudwards website.
The massive state apparatus aimed at blocking overseas sites the authorities disapprove of has been dubbed the Great Firewall of China.
What is more likely is that Mr Trump had access to a diplomatically secure satellite phone which could bypass domestic networks.
The Chinese and US are presenting a united front during Mr Trump’s visit, despite several potential points for conflict.
Speaking at a business event, Mr Trump called on the Chinese President to put more pressure on North Korea.
Mr Trump also criticised the “very one-sided and unfair” trade relationship between the two countries, but said he did not blame the country for having taken advantage.
It came as the two countries signed more than $250bn (£190bn) in business deals in the space of a few hours.
Theresa May was forced to delay a long-awaited trade mission to China in early October after Beijing chose to prioritise the visit by Mr Trump.
After the bilateral trade meetings, China announced it would start a pilot scheme to relax restrictions on foreign firms’ ownership of some businesses set up in free trade zones.