President Donald Trump told his counterpart in Afghanistan that he would mull sending more U.S. troops to the war-torn country, according to a report.

The Wall Street Journal, citing Afghan officials, reported Tuesday that Trump asked Afghan President Ashraf Ghani during a phone call in December if he needed more American troops in Afghanistan.

The phone call took place after the U.S. presidential election, when Trump was declared president-elect and Barack Obama was finishing his last weeks in the White House.

"President-elect Donald J. Trump said he would certainly continue to support Afghanistan security forces and will consider a proposal for more troops after an assessment," an Afghan official told the Journal.

The conflict in Afghanistan, which after 15 years has become America's longest war, has persisted as Taliban insurgents have continued to launch attacks and seize territory while Afghan security forces being trained by U.S. troops have made slow progress.

"The best spin the Afghan security forces can put on their activities in 2016 is that they were able to retake strategic areas that had temporarily been lost to the Taliban," John Sopko, special inspector general for Afghanistan reconstruction, said during a speech on the continuing instability in Afghanistan this month. "We're defining success as the absence of failure. At a minimum, they are playing defense and are not taking the fight to the Taliban."

Obama marked the end to combat operations in Afghanistan in December 2014. As American and NATO service members have withdrawn, the Taliban has made gains across the country, maintaining control of territory in rural areas and launching attacks on key population centers.

Top military leaders have described the security situation as a "stalemate," with Afghan security forces controlling between 65 and 70 percent of the population and the Taiban controlling 10 percent, while the remaining quarter remains contested.

Obama was forced to decelerate his plan to withdraw American troops from Afghanistan last year, leaving roughly 8,400 American troops in the country through the end of his term. The Pentagon estimates that about 6,400 troops from NATO member states are currently stationed in Afghanistan.

Trump has yet to outline a plan for dealing with the security situation in Afghanistan. Defense Secretary James Mattis, who was decisively confirmed and sworn in to lead the Pentagon on the day of Trump's inauguration, will oversee the U.S. military strategy in Afghanistan and elsewhere.