WASHINGTON (Reuters) - The top U.S. commander in Afghanistan said on Thursday he needs several thousand more international troops in order to break a stalemate in the long war with Taliban insurgents, signaling the matter may soon be put before President Donald Trump.

So far, Trump has offered little clarity about whether he might approve more forces for Afghanistan, where some 8,400 U.S. troops remain more than 15 years after the Islamist Taliban government was toppled by U.S.-backed Afghan forces.

A U.S. soldier was severely wounded in fighting in Afghanistan on Thursday, the military said.

Army General John Nicholson, who leads U.S. and international forces in Afghanistan, acknowledged Taliban gains over the past year, when deployed U.S. forces were reduced even as security deteriorated.

Nicholson said he still had enough U.S. troops to carry out counterterrorism missions against al Qaeda and other militant targets, but not enough to properly advise Afghan forces on the ground.

“We have a shortfall of a few thousand,” Nicholson told the Senate Armed Services Committee.

He added that those forces could both be drawn from the United States and from allies. Still, any increase of several thousand troops would leave American forces in Afghanistan well below their 2011 peak of more than 100,000 troops.

Nicholson noted that Trump’s defense secretary, Jim Mattis, would soon speak with allies and suggested Mattis might visit Afghanistan in the coming weeks.

That could help Mattis prepare his own recommendation to the Republican president, who has sharply criticized past U.S. administrations for their handling of conflicts in the Muslim world but has also pledged to eradicate militant Islamists around the globe.

Trump’s Democratic predecessor, Barack Obama, was often criticized by Republicans in Congress for focusing too much on driving down U.S. troop numbers in an attempt to force Afghan soldiers to become more self-sufficient.

“For too long our strategy in Afghanistan has been: Don’t lose,” said Senator John McCain, who chairs the Armed Services Committee.

Asked at one point whether a Trump administration might be more open to deciding on things like U.S. troop numbers based on concrete objectives and conditions on the ground, Nicholson responded: “Yes, sir.”

A Chinook helicopter lands to pick up U.S. soldiers of the 101st Airborne Division following a night raid in Yahya Khel, Paktika province February 21, 2011. REUTERS/Matt Robinson/File Photo

PAKISTAN POLICY REVIEW

Nicholson called for a “holistic review” of the relationship with Pakistan, echoing longstanding U.S. concerns that the Haqqani network, a militant group, enjoys sanctuary in areas in that country along the Afghan border.

“Our complex relationship with Pakistan is best assessed through a holistic review,” Nicholson said, saying that addressing U.S. concerns about Pakistan was at the top of his list of priorities to address with the Trump administration, which came into power on Jan. 20.

The United States has cut both military and economic aid to Pakistan sharply in recent years, reflecting mounting U.S. frustration with the nuclear-armed nation.

“A lot of Americans are frustrated that the bordering nation which purports to be allied on so many areas is still the source of hostile resources and fighters,” said Senator Richard Blumenthal, a Democrat.

Senator Angus King, an independent, noted that Pakistan still receives a big chunk of U.S. assistance.

“It seems to me there ought to be some connections drawn. Because they’re endangering American lives and the viability of the country of Afghanistan,” he said.

Afghan government forces control no more than two-thirds of national territory, and have struggled to contain the Taliban insurgency since the bulk of NATO soldiers withdrew at the end of 2014.

It is also struggling with other militants, particularly from Islamic State’s Afghanistan branch. Islamic State claimed responsibility for a suicide attack that killed at least 22 people outside Afghanistan’s Supreme Court on Tuesday.

A number of provincial capitals have been under pressure from the Taliban while Afghan forces have been suffering high casualty rates, with more than 5,500 killed in the first eight months of 2016.