John Kerry did not make the best of starts to his trip to Number 10 - he whacked his head on the door.

The US secretary of state, visiting new Prime Minister Theresa May, posed for photographers before turning to enter the famous black door.

But he was unaware it had been partially shut behind him.

But Kerry seemed to recover quickly and was pictured chatting with May inside Downing Street.

After the talks, Kerry said the prime minister was committed to a "calm, thoughtful, reasonable" way to deal with Brexit.

"The prime minister and I had an excellent discussion and I'm very grateful to her for her restatement of the commitment to the very strong transatlantic partnership," he said.

Kerry will also hold talks with his counterpart, new Foreign Secretary Boris Johnson, during the visit to London.

Johnson is hosting talks on Syria with his counterparts from the US, Germany, France and Italy, along with EU foreign affairs chief Federica Mogherini.

"I will be making clear my view that the suffering of the Syrian people will not end while Assad remains in power. The international community, including Russia, must be united on this," Johnson said.