Barack Obama has held talks with Rishi Sunak as the former US president paid a “courtesy visit” to Downing Street during a trip to London. The pair are understood to have discussed a range of subjects during an hour-long meeting, including one of the prime minister’s favourite topics, artificial intelligence. Obama, who served two terms in the White House from 2009 to 2017 before he was succeeded by Donald Trump, was in London as part of work with his Obama Foundation, which oversees a scholarship programme and other initiatives. The prime minister’s official spokesperson said Obama had made “an informal courtesy drop-in as part of his trip to London”. He added: “I think President Obama’s team made contact and obviously the prime minister was very happy to meet with him and discuss the work of the Obama Foundation.” The two held what were understood to be largely one-to-one discussions in the prime minister’s study. Obama briefly paused at the door of No 10 to wave to the cameras but no photos were released from what Downing Street said was a private meeting. As Obama left Downing Street in the company of the US ambassador to the UK, Jane D Hartley, he was asked by the media for his opinion on the state of Russian democracy and replied: “I’m tempted!” The former president later met the Labour leader, Keir Starmer. Obama previously visited Downing Street in April 2016 when David Cameron was prime minister. Lord Cameron, the foreign secretary, is understood not to have been present at Monday’s discussions. Despite early suggestions of a “bromance” when both men were in power, their public utterances about each other have been mixed. Obama suggested in 2016 that Cameron was distracted by domestic priorities as Libya descended into a “mess”. He also said he warned his British counterpart that the “special relationship” would be at risk if the UK did not commit to spending 2% of national income on defence, in line with Nato targets. Cameron was withering of Obama in his autobiography, accusing him of “dithering” on Libya and of being “clearly frustrated he had been sucked in”.