"This is the only way to achieve a strong and sustainable peace in Sri Lanka in which all communities can prosper," said a statement issued by the British High Commission in Colombo.
The joint statement was by Lord Malloch-Brown, Minister of State for the Foreign and Commonwealth Office of the British Government and Douglas Alexander, Secretary of State for International Development.
It said the British government was closely following developments after the fall of Kilinochchi, a Tiger stronghold in the northern region known as the Vanni on January 2.
"This development makes it even more urgent that all parties achieve progress on setting out a political solution that addresses the legitimate concerns of all communities," the statement said.
"We remain concerned about the humanitarian impact of the conflict and call on all parties to abide by their obligations under international humanitarian law."
The statement said Britain was particularly concerned about the need to ensure t