Britain's Foreign Secretary David Miliband says he is gravely concerned about the continued fighting between government forces and Tamil Tiger rebels in northern Sri Lanka.
Miliband said Saturday the conflict threatens the lives of tens of thousands of civilians trapped in the war zone, and repeated his call for an immediate cease-fire to allow civilians to flee the fighting.
Miliband said British Prime Minister Gordon Brown's special representative, Des Browne, will travel to New York to consult urgently with the United Nations.
U.N. official Vijay Nambiar met with Sri Lankan President Mahinda Rajapaksa and other officials Friday to discuss the fate of civilians and efforts to free them from the war zone.
In Paris, thousands of ethnic Tamils demonstrated Saturday to demand an immediate cease-fire in Sri Lanka.
An estimated 100,000 civilians are trapped along with the remaining Tamil Tiger forces in a small sliver of land in the island's northeast, surrounded by government troops.
The U.N. refugee agency said Friday that the humanitarian situation for civilians in the conflict zone is worsening because of flooding caused by heavy rains and winds.
The Tamil Tigers have been fighting for 25 years to create an independent homeland for Sri Lanka's Tamil minority. More than 70,000 people have been killed in the civil war.
On Friday, a British court in London convicted prominent British Tamil leader Arunachalam Chrishanthakumar of supplying bomb-making materials to the rebels.
Britain, the United States and the European Union consider the Tamil Tigers a terrorist organization.