Peacekeeping forces led by NATO could be in Afghanistan for up to 10 years, with the number of soldiers growing as rehabilitation expands, a commander said on Friday. Pressure has been growing on NATO members to contribute more soldiers to the International Security Assistance Force (ISAF). ‘‘ISAF and NATO will stay as long as the Afghan people want us to stay,’’ said Maj-Gen Andrew Leslie, commander of Canadian forces in Afghanistan and ISAF’s deputy commander.“How long is NATO willing to stay? Somewhere between fiveto 10 years, or even as long as it takes,” he told a news conference.