LONDON (AP) — Former British Prime Minister Tony Blair said Wednesday that the West must do all it can to persuade Syrian President Bashar Assad to step down but warns that the country would face acute divisions if Assad is ousted.

With a loosely linked group of rebel forces trying to overpower the regime, Blair said in an interview with The Associated Press that he fears unifying the country would be the toughest challenge in a post-Assad Syria.

"It's very clear that in the end this regime will change," said Blair, who serves as special envoy for the Quartet on the Middle East, a diplomatic peace initiative. "What we've got to do is both to hasten its end because the truth is, it's lost the ability and the legitimacy to govern the country, but we've then got to work with everybody to construct the aftermath in the right way."

Syrian rebels appear to be taking more territory as they advance in an uprising that has morphed into a civil war. A string of recent high profile defections from Syria's powerful 300,000-man-strong military hint the regime could be weakening.

"The sooner it ends the sooner the slaughter will end and also the sooner you can try and repair what will now be deep, deep hatreds amongst parts of the community there," Blair said in London after appearing at a conference organized by Beyond Sport, a group that uses sports to promote social development.

"The powerful lesson from any of these countries now is when you lift the lid off what is a situation of dictatorship and try to move it towards democracy, then you've got to be prepared to manage a lot of religious and tribal and ethnic problems that are going to be very acute," Blair said.

Blair said he believes "the West should ramp up the pressure" on Assad but said at this point he would not support the kind of NATO intervention that toppled Libya's longtime dictator Moammar Gadhafi last year.