The White House has said that President Barack Obama is "entirely confident" he and his successor can effectively coordinate with Theresa May if she is the next British PM - and that the special relationship will continue.

Josh Earnest, Mr Obama's spokesman speaking at a press briefing at the White House:

What's Mr Obama's reaction to the news?

"President Obama had an opportunity to visit with Prime Minister Cameron at the Nato summit in Warsaw over the weekend. The two leaders sat next to each other for hours on end at that summit, so I know they had an opportunity to have a number of conversations. I'm not aware at that point however that Prime Minister Cameron shared his plans with president Obama. I've learned a lot about the British political process in just the past few hours, so it's my understanding that having one of the two competitors for the leadership of the Conservative Party drop out essentially made the choice a foregone conclusion. So my understanding is that there's some ceremonial steps that have to take place here. Ultimately this is a British political process that will follow the guidelines that are in place. The president continues though to rest on the principal that the relationship between the United States and the United Kingdom is a special one, and it is one that transcends the personalities or political parties of either country's leader. If in fact Theresa May is the next Prime Minister of the UK, the president is entirely confident that he and his successor will be able to coordinate effectively with her to not just protect but even advance the special relationship between our two countries."

Does he know Theresa May?

"The answer to that is yes, I don't know that they've had a detailed conversation. I know that she participated in the expanded bilateral meeting that President Obama had with Prime Minister Cameron when he was there earlier this spring. I only know that because I met her in the context of that meeting. But I don't know that they've had an extended conversation before."

On Brexit means Brexit

"The president's views on this have not change... He's spoken at length on this... Our expectation is that the Brexit process will be one that will commence when leaders in the UK invoke Article 50 of the EU charter, and that will precipitate a negotiation between EU officials and UK officials - should be done in orderly fashion that doesn't disrupt either EU or UK economies."