WASHINGTON (AP) — President Barack Obama's choice to be the top commander in Afghanistan said Thursday he envisions a U.S. presence in the country after American combat forces leave at the end of 2014, despite a national war-weariness reflected in Congress.

Gen. Joseph Dunford, the assistant commandant of the Marine Corps who has directed combat forces in Iraq, told a Senate panel that the two main missions for an enduring force would be counterterrorism and assisting Afghan security forces. Pressed on numbers, Dunford declined to provide specifics but did say 1,000 troops would not be sufficient.

About 68,000 U.S. troops are still serving in a war that has dragged on for more than a decade. The Obama administration is expected to announce in the coming months the pace of the U.S. troop drawdown next year.

Dunford is poised to replace Gen. John Allen, whose nomination to take over in Europe is on hold as he's suddenly entangled in a sex scandal that has led to the resignation of CIA director David Petraeus. Allen had been scheduled to testify Thursday but now is the subject of a Pentagon investigation for potentially inappropriate communications.

Allen is due to make a recommendation to Defense Secretary Leon Panetta in the near term on the pace of the withdrawal.

In his testimony, Dunford was asked if the U.S. and coalition forces are winning the Afghan war.

"We're making progress," said Dunford, who recently traveled to Afghanistan. "I believe our objectives are achievable."

The Marine Corps general said crucial for Afghanistan will be elections next year that will ensure whether the financial commitments of other foreign nations are fulfilled. He also said that they would engender confidence in the country.

President Hamid Karzai has indicated that he would not seek another term.

Looking beyond 2014, Sen. Lindsey Graham, R-S.C., pointed out that Afghanistan does not have an Air Force and would likely need attack helicopters and other airpower as well as intelligence capability.