Afghanistan's Taliban insurgents on Sunday denied that they had resumed talks with the United States, while the Afghan government insisted that the peace process was "on track".

The Taliban, who last month broke off contacts with the US in Qatar, said they would not resume talks "until the Americans take constructive steps and fulfil promises which were agreed upon for confidence building".

Among the confidence building measures proposed is the release of five Taliban leaders held at the US military prison in Guantanamo Bay.

The statement, posted on the Taliban website, came just days after the US, Afghanistan and Pakistan agreed at a meeting in Islamabad to look at ways to provide safe passage to Taliban who are willing to join the peace process.

That move was also rejected by the hardline Islamists, who said it was aimed at facilitating militants "kowtowing to US demands in the name of supposed reconciliation talks".

"The Islamic Emirate of Afghanistan, hereby, strongly denounce such foul and horrendous rift-creating attempts," the Taliban said in a separate statement by spokesman Zabihullah Mujahid.

But in Kabul on Sunday, the Afghan government said progress was being made in efforts to negotiate an end to the decade-long war.

"The peace process is still on track with the Taliban and also efforts are underway by the Afghan government for setting up a Taliban address in the Gulf state of Qatar," foreign ministry spokesman Janan Mosazai told a news conference.

The Taliban, however, have always dismissed the idea of talks with the Afghan government, describing it as a puppet of the Americans.

For its part, Washington has consistently said that any talks with the Taliban to end the war could only take place with the agreement of the Afghan government, which eventually should lead the process.

Mosazai said the idea of safe passage aimed to provide "a guarantee to Taliban leaders and officials to safely approach the Afghan government or to travel from one country to another country to engage in direct negotiations with the Afghan government".

Senior Taliban leaders operate from bases within neighbouring Pakistan, which the Afghan government accuses of supporting the militants.