The US envoy negotiating with the Taliban will hold new talks this month with the insurgents in Qatar, the State Department said Saturday, as momentum builds for a deal to end America's longest war.

Zalmay Khalilzad, a veteran US policymaker who is leading President Donald Trump's push to broker a peace deal with the Taliban, left Friday on a 17-day trip that will also take him to Afghanistan, Pakistan, Germany, Belgium and the United Arab Emirates, the State Department said.

In Doha, he will resume talks with the Taliban after a break of around a month "to move the peace process forward," the State Department said in a statement.

Khalilzad has already met six times with the Taliban in recent months as he looks to seal a deal under which the United States will pull out troops who were first deployed following the September 11, 2001 attacks.

The United States and the Taliban are believed to have largely agreed on the key demand of Washington from 2001 and again now — that the Taliban not allow Afghanistan to be used by violent extremists.

But a major sticking point remains the refusal of the Taliban to negotiate with President Ashraf Ghani's government, which enjoys international support.

The Taliban, believing they have leverage on the military front, have also rejected Ghani's overtures for a nationwide ceasefire.

"No one should expect us to pour cold water on the heated battlefronts of jihad or forget our 40-year sacrifices before reaching our objectives," Taliban chief Haibatullah Akhundzada said in a rare message released Saturday.

In Kabul, Khalilzad will meet representatives of civil society and women's rights groups, which have been especially concerned about a larger role for the Taliban.

Khalilzad will "encourage all parties to work towards intra-Afghan negotiations that lead to a final peace settlement," the State Department said.

Germany, another of Khalilzad's stops, has voiced willingness to hold a meeting on peace in Afghanistan.

He will start his trip in Pakistan, the chief backer of the Taliban before September 11, which has used its contacts to facilitate the talks with the Taliban.

Four Afghans killed, four US troops wounded in Kabul suicide blast
Kabul (AFP) May 31, 2019 –

At least four Afghans were killed and four US troops lightly wounded when a car bomber attacked a US military convoy in Kabul on Friday, officials said.

The blast, which was claimed by the Taliban, occurred around 8:40 am (0410 GMT) when an explosives-laden vehicle drove into the convoy that was travelling in eastern Kabul, according to interior ministry spokesman Nasrat Rahimi.

"Unfortunately in the attack, four of our countrymen were martyred and three others wounded — they were passers-by," Rahimi said.

A spokesman for Resolute Support, the US-led NATO mission in Afghanistan, said four US service members had suffered minor injuries.

When US forces move about in Kabul, they typically travel in tall, heavily reinforced tactical vehicles that can provide good protection against bombs.

Known as MRAPs, for Mine-Resistant Ambush Protected, the vehicles are sturdy but present a very visible target.

Taliban spokesman Zabihullah Mujahid said the insurgent group was behind the attack, which he claimed to have killed "10 officers and soldiers of invading forces".

The Taliban frequently exaggerate claims after attacks.

The blast came one day after an Islamic State suicide bomber blew himself up outside an Afghan army military academy, killing at least six people.

It also followed a meeting between the Taliban and Afghan opposition figures in Moscow this week that yielded no tangible results.

Afghan President Ashraf Ghani had proposed a nationwide ceasefire at the start of the holy month of Ramadan, but the Taliban rejected the offer and violence continues apace across the country.