Britain's Defense Secretary Des Browne on Monday announced the deployment of 1,400 extra troops to Afghanistan to tackle a threatened Taliban spring offensive, days after Tony Blair announced a major withdrawal from Iraq.

The announcement will bring the total U.K. troop level in Afghanistan to around 7,700 until 2009, meaning Britain will have more forces based there than in Iraq for the first time since the 2003 Iraq invasion. Blair said Wednesday that Britain would soon reduce numbers in Iraq to 5,500.

Britain currently has around 5,500 troops in Afghanistan, mainly based in the volatile southern province of Helmand, a Taliban stronghold and center of the country's opium trade.

Browne previously authorized deployment of an extra 800 troops to the region on Feb. 1, but failed to persuade several other NATO countries to contribute new combat troops during a summit in Seville, Spain, earlier this month.

"It is increasingly clear, that at present, when it comes to the most demanding tasks in the most challenging parts of Afghanistan, only a small number of key allies are prepared to step forward," Browne told the House of Commons.

Lawmakers in Britain, the United States, Canada and other nations with troops in southern and Afghanistan have been angered by the reluctance of some European allies to commit extra troops to the 35,500-strong NATO force, and in particular to allow their soldiers to be deployed to the Taliban's heartland in the south and east.

Both France and Germany raised doubts about the need for more troops during the NATO conference.

Browne said Britain, the United States and others were "shouldering a greater burden than we like" in leading the alliance's mission to oust Taliban loyalists and extend the reach of President Hamid Karzai's Kabul government.

But he told lawmakers that failing to deploy additional combat troops posed "too great a risk to progress achieved" so far by the mission.

Opposition Conservative lawmaker Liam Fox said the failure of several NATO countries to match the commitment shown by Britain, the United States, Canada and the Netherlands, called the future of the alliance into question.

"If NATO is to exist and flourish in the future, this is not a tenable position," Fox told lawmakers during the session.

However, NATO Secretary-General Jaap de Hoop Scheffer said Monday he believed alliance members were aiding the mission.

"I do not share the analysis that other nations are not stepping up to the plate because we have seen many allies ... announcing or making effective an increase in their contribution," he said.