KABUL • More than 18 years after the United States invaded Afghanistan, President Donald Trump has conditionally approved a peace deal with the Taleban that would withdraw the last American troops from the country, potentially beginning the end of America's longest war, according to Afghan and US officials.

But the deal will be signed only if the Taleban proves its commitment to a durable reduction of violence over a test period of about seven days later this month.

If the Taleban does end hostilities and a deal is signed, the US would then begin a gradual withdrawal of American troops, and direct negotiations would start between the Taleban and Afghan leaders over the future of their country.

Secretary of State Mike Pompeo informed Afghanistan's top leaders in separate phone calls on Tuesday that Mr Trump had given tentative approval to this approach, according to a senior Afghan official briefed on one of the calls.

A senior US official aware of the developments also confirmed that Mr Trump had given his preliminary approval for a deal on Monday, dependent on a cessation of violence. That was the same day he visited Dover Air Force Base to receive the remains of two soldiers, the latest US fatalities in the war, which has killed tens of thousands of Afghans and more than 3,500 American and coalition troops since the US drove the Taleban from power in 2001.

A senior diplomat in Washington described the deal as "95 per cent agreed to in principle", but that the possibility of a final agreement will become clearer in a matter of a couple weeks.

A senior Taleban official informed of the negotiations said that there were now "positive movements", but declined to discuss details because the group's internal deliberations were continuing.

While the move could mark a significant moment in Mr Trump's pledge to end what he has described as "endless wars", the talks have long remained fragile and previously broke down just as a signing was near.

After nearly a year of negotiations, the two sides were on the verge of a similar deal last September.

Mr Trump suddenly called off the talks, citing a Taleban attack that killed an American and Nato soldier and nearly a dozen Afghans.

But officials said it was largely because Mr Trump's grand gesture of inviting the Taleban to Camp David to finalise the deal fell apart.

After that, it took months of trust-building work, including a prisoner exchange, to get back to the negotiating table.

NYTIMES