While details of the deal have not been announced, it is widely expected the US will slash its troop presence in Afghanistan in return for various Taliban commitments AFP/Wakil KOHSAR

In a weekend bombshell, Trump said that he had planned previously unknown talks with the two sides Sunday in Camp David, the presidential retreat in Maryland, but that the Taliban's persistent, grisly campaign of violence made them untrustworthy partners.

"Unbeknownst to almost everyone, the major Taliban leaders and, separately, the President of Afghanistan, were going to secretly meet with me at Camp David on Sunday," Trump said in a tweet.

"Unfortunately, in order to build false leverage, they admitted to an attack in Kabul that killed one of our great great soldiers, and 11 other people. I immediately cancelled the meeting and called off peace negotiations."

"What kind of people would kill so many in order to seemingly strengthen their bargaining position? They didn't, they only made it worse!" Trump said.

A US soldier and another service member from Romania were killed in a car bombing Thursday in Kabul - the latest major attack claimed by the Taliban even as they negotiated with a US envoy.

According AFP, if realized, the summit would have been the latest high-profile, high-stakes diplomacy by President Trump.

Instead, his announcement by tweet ended a painstaking diplomatic process led for nearly a year by Zalmay Khalilzad, the Afghan-born veteran US diplomat who has been meeting with the Taliban in Qatar.

Afghanistan's internationally recognized president, Ashraf Ghani, had been outspoken in his criticism of the shape of the withdrawal agreement with the Taliban, who have refused to negotiate with his government.

Khalilzad had said in Kabul that he had reached an agreement in principle with the Taliban.

According to parts of the draft deal that had been made public, the Pentagon would pull about 5,000 of the roughly 13,000 US troops from five bases across Afghanistan by early next year.

The insurgents in turn will renounce Al-Qaeda, promise to fight the Islamic State group and stop jihadists using Afghanistan as a safe haven.

The fight against Al-Qaeda was the initial reason for the US-led war that overthrew the Taliban following the September 11, 2001 attacks on the United States.

But US public opinion has soured on nearly two decades of war and Trump, after initially being persuaded to reinforce US troops, has said that the United States should not be involved in "endless" war.

Trump had been uncharacteristically reticent about Afghanistan in recent weeks, with all eyes on whether he would approve a final deal.

Washington had hoped that a withdrawal of US troops would lead to negotiations between the Taliban and Kabul on a more permanent peace.

Speaking earlier on Sep 7 in Paris, Defense Secretary Mark Esper said that the United States would only accept a "good deal" with the Taliban - words welcomed by the government in Kabul.

But Trump's abrupt announcement draws a new question mark on whether the United States will leave Afghanistan anytime soon.

The decision comes weeks before Afghanistan is set to hold elections, an unwieldy exercise even in more stable times./.

VNF/AFP