LONDON  Entering a debate that has stirred political tumult in Britain, Vice President Joseph R. Biden Jr. said in an interview broadcast Thursday that more coalition troops would die in Afghanistan but that the war was “worth the effort.”

Speaking during a tour of Ukraine and Georgia, Mr. Biden told the BBC that the lawless region along the Afghanistan-Pakistan border was “a place that, if it doesn’t get straightened out, will continue to wreak havoc on Europe and the United States.”

His remarks have a particular resonance in Britain at a time when the American-led coalition has recorded some of its worst casualties since the overthrow of the Taliban regime in 2001.

Britain has some 9,000 soldiers in Afghanistan  the second biggest contingent after the United States  and so far this month alone has lost 19 soldiers. That brings Britain’s total since 2001 to 188, higher than its death toll in the Iraq war. The latest fatalities came Wednesday, when bombs killed two United States service members and one Briton in southern Afghanistan.