Barack Obama has spoken out about Republican plans to repeal and replace his healthcare system, attacking what he called the "fundamental meanness" of their bill, and urging them to reconsider.

The proposal was published on Thursday, with Republicans hoping to secure its approval within a week.

That looks unlikely, given that four senators said hours after the bill was published that they could not vote in its favour. That is a problem for the party leadership - Republicans hold 52 out of 100 Senate seats, so they can afford only two defections.

Mr Obama, writing on Facebook, urged all senators to reject the proposal.