By Jonathan Moore and Alex Stevenson
David Miliband is in Sri Lanka today seeking to persuade the Colombo government to temporarily cease fighting with the Tamil Tiger rebels.
The foreign secretary is on a one-day tour of the country with French counterpart Bernard Kouchner, who already appears to have acknowledged their mission will not succeed.
"We tried very hard, we insisted, and we insisted, but it is up to our friends to allow it or not," the AFP news agency quoted Mr Kouchner as saying after talks with Sri Lankan foreign minister Rohitha Bogollagama.
Sri Lankan government forces are bringing about the final defeat of the separatist Tamil Tigers, who are putting up a bitter fight as their 20-year struggle comes to an end.
An estimated 50,000 civilians are still trapped in the warzone between the government and rebel fighters and the UN has said almost 6,500 have already been killed in the fighting.
"Sri Lanka has suffered terribly from terrorism over the last 25 years," Mr Miliband said.
"The fighting must stop. Repeated international calls for a stop to the fighting are motivated entirely by concern for innocent civilians."
"There must be wider and fuller access for the UN and international aid agencies to civilians in the "no fire zone", during the screening process, and in the IDP camps."
Sweden's foreign minister Carl Bildt was due to travel with Mr Miliband but was denied entry for reasons he described as obscure and the Swedish have withdrawn their ambassador in protest of the decision.
The Sri Lankans have said the denial was a mistake and Mr Bildt would be welcome to visit next month but the Czech presidency of the EU said the decision was a "grave" error.
The visit follows weeks of prolonged and heated protests outside parliament urging the government to take action.
One protestor has been on hunger strike for more than three weeks and fellow protestors fear he is close to death.
Mr Miliband's visit is the latest in a line of measures taken by the government to try and limit casualties to civilians in the region including a visit by international development minister Mike Foster and a pledge by Gordon Brown of £2.5 million in humanitarian aid.
Mr Brown also spoke to the Sir Lankan president Mahinda Rajapaksa over the weekend to reiterate calls to end the conflict and raise concerns over the welfare of displaced civilians.