The US could send an additional 3,000 troops to Afghanistan – or perhaps more – as part of a major shift away from the policy of President Donald Trump’s predecessor Barack Obama.

Senior Trump administration and military officials are reportedly recommending the expansion of the US’s military strength in the country to aid Afghan security forces and push back against a resurgent Taliban.

The White House would have to approve the proposals, likely before the next Nato meeting on 25 May in Brussels.

There are 13,000 Nato troops currently in the country, 8,400 of which are from the US. More than 2,000 of them are involved in missions against terrorist groups Isis and al-Qaeda, but the majority are part of a mission that trains, advises and assists Afghan security forces in their fight against the Taliban insurgency.

The recommendations come after General John Nicholson, commander of the American-led international military force in Afghanistan, told Congress in February that he needed a few thousand more troops to effectively train and advise Afghan soldiers, warning that the US and its Nato allies were facing a military deadlock, 15 years after first sending troops to the country.

Afghan forces have had heavy casualties over the past year as they have tried to prevent the Taliban from capturing provincial capitals.

President Donald Trump has yet to announce his decision on his Afghan strategy. During the campaign, he repeatedly said that he would put “America first”, expressing scepticism about allowing the US to get caught up in foreign conflicts, while also vowing to defeat Islamist extremists.

The US military presence in Afghanistan began in 2001, in response to the 11 September terror attacks.

The amount of US troops remained low in the country compared to other large operations in Iraq that started in 2003. After a 30,000-troop reinforcement in 2009 under Mr Obama, the number reached a peak of 100,000 in 2010.

The Obama administration set in place timelines for reducing the number of US troops as Afghan forces became more in charge of their own security.

The question is whether US and Afghan forces, even if bolstered by a new strategy involving more troops and authorities to target the Taliban, can bring enough pressure to push the war toward a settlement. Critics against an escalation have argued that even the Obama-era surge did not bring any Taliban concessions.

Former Secretary of State Condoleezza Rice said on Tuesday that the President will need to better explain his strategy after more than a decade of conflict.

“What is the strategy now?” Ms Rice told NBC. “It doesn’t make sense to increase troop strength to keep doing the same thing.”

During the White House press briefing, Press Secretary Sean Spicer said he thinks that Mr Trump has asked his national security team to rethink the US's strategy for how it approaches the conflict in Afghanistan, as well as how to attack ISIS.

“How do we win? How do we eliminate the threat?” Mr Spicer said. “And I think doing that isn’t just a question of throwing money or people, but looking at the mission and the strategy. And that is what the team has been doing holistically.”

The news came as Afghan security forces battle Taliban fighters blocking a main route into the northern city of Kunduz with improvised explosives, as fears grew local residents could be forced to flee the city.

Heavy fighting has been under way for days around Kunduz, a city that the Taliban have twice come close to capturing in recent years, and government reinforcements included special forces units rushed to the province to bolster defences.

“A fight is going on between Afghan forces and the enemy around Kunduz city,” said defence ministry spokesman Mohammad Radmanish, adding that three operations were under way. “We have the capacity and enough reinforcements to tackle them,” he said.

The heavy fighting, which follows the start of the Taliban’s offensive last month, has underlined warnings of another difficult year for Afghan forces. They suffered 6,785 deaths last year and control only around 60 percent of the country.