The next head of Britain's army says his country's involvement in Afghanistan could last for up to 40 years.

General David Richards told the British newspaper The Times in an article published Saturday that the whole process in Afghanistan could take "30 to 40 years." 

The general, who officially becomes the top army officer on August 28, said there is "no chance" of NATO forces pulling out of Afghanistan, because they must now focus on nation building, including the expansion of the Afghan army and police force.

However, Britain's Shadow Defense Secretary Liam Fox told The Times that a 30 to 40-year commitment in Afghanistan was "unaffordable" and would require a "total rethink" of British foreign and security policy.

NATO Secretary-General Anders Fogh Rasmussen told British radio (BBC) Friday that progress has been made against insurgents in southern Afghanistan because of a recent increase in troop numbers there. 

Rasmussen, a former Danish prime minister, also said gradually handing over security to the Afghan army and police will be a key marker of success for NATO.

The United States has already said its commanders are considering asking to deploy more soldiers, and Georgia's parliament has approved plans to send more troops.  But Thursday Canada's foreign minister confirmed his country's troops will go home as planned by 2011. 

Some information for this report was provided by AFP.