At least 25 Afghan security force personnel were killed in an ambush blamed on the Taliban, officials said Wednesday, as spiralling violence imperils ongoing peace talks.

The ambush came despite assurances by the Taliban to Washington last week that they would reduce bloodshed. Security forces were attacked overnight Tuesday in Takhar province and fighting was still going on, said Jawad Hejri, a spokesman for the governor, who put the death toll so far at 25.

"The Taliban had taken positions in the houses around the area. They ambushed our forces who were there for an operation against the enemy," he said.

Takhar provincial health director Abdul Qayoum said 34 security personnel had been killed -- including the deputy police chief of the province. The Taliban have so far not commented on the attack.

Despite opening peace talks with the Afghan government in Qatar, the hardline group have only increased violence in Afghanistan in a bid to wield leverage in the negotiations. A major assault by the Taliban in Helmand province forced thousands of families to flee their homes last week, while a car bomb Sunday near the police headquarters in Ghor blamed on the insurgents left 16 people dead and 154 wounded.

Meetings have been held between Afghan forces and the Taliban in Doha over the past few days, but little progress has been made since the talks launched in September.

"This level of violence, of course, makes the task of negotiating very difficult," said Nader Naderi, a negotiator for the Afghan government. "Situations like this add to the sense of urgency for a ceasefire."

The top US envoy to Afghanistan, Zalmay Khalilzad, said earlier this week that fighting is threatening the peace process. "Violence today remains distressingly high in spite of the recent reaffirmation of the need for substantial reduction," he added.

US influence over Afghanistan's battlegrounds is on the wane, however, with the Pentagon looking to withdraw all its remaining troops by next May.

With US elections less than two weeks away, President Donald Trump is trying to make good on his promise to end America's longest war and pull back troops even sooner.

It has raised questions about Washington's insistence that its withdrawal from Afghanistan after 19 years of war is really "conditions-based". The Taliban have been quick to exploit the apparent lack of resolve, and began to push for fresh military gains as soon as they signed the withdrawal deal with the US.