KUNDUZ - Taliban militants killed at least 20 Afghan soldiers and policemen in a string of overnight attacks, Afghanistan government officials said on Wednesday.

In response to the insurgent attack on Afghan forces, the US forces hit Taliban fighters with an air strike for the first time in 11 days, an American military spokesman said.

The US airstrike in southern Helmand province -- the first in 11 days -- came hours after US President Donald Trump told reporters he had had a “very good” chat with the Taliban political chief, who on Saturday signed a historic deal with Washington to withdraw foreign forces.

“Taliban fighters attacked at least three army outposts in Imam Sahib District of Kunduz last night, killing at least 10 soldiers and four police,” said Safiullah Amiri, a member of the provincial council. A defence ministry official speaking on condition of anonymity confirmed the army toll, while the provincial police spokesman Hejratullah Akbari confirmed the police fatalities.

The insurgents also attacked police in central Uruzgan province Tuesday night, with the governor’s spokesman Zergai Ebadi telling AFP: “Unfortunately, six police were killed and seven wounded.”  The violence has cast a pall on the nascent Afghan peace process, with the insurgents clashing with Kabul over a prisoner exchange ahead of talks that are due to begin on March 10.

On Tuesday Trump told reporters in Washington that he had a “very good” relationship with Taliban political chief Mullah Baradar, with the pair speaking on the phone for 35 minutes, according to the insurgents.

“The relationship is very good that I have with the mullah. We had a good long conversation today and you know, they want to cease the violence, they’d like to cease violence also,” he said. Trump has touted the Doha deal as a way to end the bloody, 18-year US military presence in Afghanistan -- right in time for his November re-election bid.

On the other hand, the US military launched an airstrike against Taliban fighters to defend Afghan forces Wednesday. Since the signing in Doha however, the militants have ramped up violence against Afghan forces, ending a partial week-long truce that provided a rare reprieve to war-weary residents.

US Forces-Afghanistan spokesman Sonny Leggett tweeted that the airstrike took place against Taliban fighters who were “actively attacking” an Afghan forces checkpoint in Helmand province.

“This was a defensive strike to disrupt the attack,” he tweeted. “We call on the Taliban to stop needless attacks and uphold their commitments. As we have demonstrated, we will defend our partners when required.” He said insurgents had carried out 43 attacks on checkpoints in Helmand on Tuesday alone.

The insurgents killed at least 20 Afghan soldiers and policemen in a series of overnight attacks, government officials told AFP Wednesday, casting a pall over peace talks between Kabul and the Taliban, due to begin on March 10.