Afghanistan's government would collapse within weeks if NATO troops left the country right away, Britain's Foreign Secretary David Miliband said in an interview published Saturday.

Miliband, who was in Afghanistan for the inauguration of Afghan President Hamid Karzai last week, said insurgent forces would quickly overrun Afghan troops if the international community pulled out.

"If international forces leave, you can choose a time — five minutes, 24 hours or seven days — but the insurgents would overrun those forces that are prepared to put up resistance and we would be back at square one," he told The Guardian newspaper.

Karzai has said he expects Afghan forces to be able to control the country within five years. Miliband said the international community would stay as long as needed.

"Artificial timetables just give succor to your enemy," Miliband added.

Prime Minister Gordon Brown told lawmakers last week that Britain remains committed to the Afghanistan mission — despite some public calls for troops to be withdrawn amid a mounting death toll. Some 235 British troops have died in Afghanistan since operations began in 2001.

Taliban insurgents have grown bolder in Afghanistan recently, challenging the weak central government led by President Hamid Karzai.

Karzai's own position has been undercut by an election victory tainted by credible charges of widespread fraud. Brown and other Western leaders have warned Karzai that he cannot count on continued support until he moves to stamp out corruption.