President and PM try to show united front on Libya

David Cameron's hopes of bringing a swift end to the military stalemate in Libya suffered a rebuff when Barack Obama warned that the conflict could drag on for months.

The Prime Minister and the US President played down the differences between them over the likely timescale of the mission in Libya and insisted the Nato operation would succeed in driving Colonel Gaddafi from power.

British ministers want to see the two-month air campaign stepped up in the next few weeks. After discussing Libya with Mr Obama in Downing Street during his state visit, Mr Cameron said: "The President and I agree that we should be turning up the heat in Libya. I believe the pressure is on that regime."

However, Mr Obama warned against "any artificial timeline in terms of how long this would take". While promising there would be "no let-up" in the pressure on Colonel Gaddafi, he said: "Ultimately this is going to be a slow, steady progress in which we're able to wear down the regime forces and change the political calculations of the Gaddafi regime to the point where it finally realises it is not going to control this country."

The President insisted the US was still playing a key role in the air campaign despite scaling down its involvement. The President insisted that the decision not to send ground troops to Libya required a bottom-up solution involving the opposition forces. "There may be a false perception that there are a whole bunch of secret super-effective air assets in a warehouse somewhere that could just be pulled out and that would somehow solve the situation in Libya. That's not the case," he insisted.

Mr Cameron and Mr Obama toned down their earlier threat to take military action against other autocratic rulers in the Arab world, such as Syria. They both stressed their desire to depart from the interventionism of George Bush and Tony Blair. Mr Cameron said: "Democracy is built from the ground up. You've got to work with the grain of other cultures, and not against them."

Mr Obama added: "We are making sure that as we promote democracy and human rights, that we understand the limits of what the military alone can achieve; and that we're mindful that the fate of these regions is going to be determined by the people there themselves, and that we're going to have to work in partnership with them."