OBAMA, CAMERON REAFFIRM AFGHAN'S WITHDRAWAL STRATEGY

UNITED States (U.S.) President Barack Obama and visiting British Prime Minister David Cameron have ruled out any dramatic changes to plans to withdraw international forces from Afghanistan by the end of 2014 in the aftermath of the alleged slaughter of Afghan civilians by an American soldier.

'I don't anticipate, at this stage, that we're going to be making any sudden, additional changes to the plan that we currently have,' Obama said as he and Cameron held a joint media briefing in the White House's Rose Garden.

The president acknowledged 'a hard slog' in America's longest war but he and his guest 'reaffirmed the transition plan' and vowed: 'We're going to complete this mission, and we're going to do it responsibly.'

'We will not give up on this mission,' agreed Cameron.

The two leaders also discussed efforts to pressure Iran over its suspect nuclear programme, and Syria over its bloody crackdown on opposition to Bashar al-Assad, as well as effort to steer the global economy on a path to renewed prosperity.

Cameron said America and Britain sought a peaceful transition in Syria 'rather than revolution or civil war' but warned that could be the outcome unless Assad changes his approach.

The prime minister also said that Britain was pledging another ?2 million in food and medicine to international humanitarian efforts.

On Iran, Obama warned Tehran that international talks set to resume were Tehran's 'best bet' to find a peaceful end to the standoff over its nuclear program, which Washington charges hides an attempt to develop the ability to build an atomic weapon. Iran denies the accusations.

At Cameron's formal welcoming ceremony earlier, the two leaders exchanged jokes about British forces burning the White House during the War of 1812 and quips anchored on Irish writer George Bernard Shaw's observation that America and England are two nations 'divided by a common language.'