Secretary of State Mike Pompeo informed Afghanistan’s leaders Tuesday of what President Ashraf Ghani said was “notable progress” in ongoing U.S. peace talks with the Taliban.

Ghani and Afghan Chief Executive Abdullah Abdullah, who received separate calls from Pompeo, both expressed optimism about a potential “reduction in violence,” but indicated in statements on Twitter that no final agreement had been reached.

The talks, which have been taking place in Doha, Qatar, have most recently revolved around the length of such a reduction, which people knowledgeable about the negotiations said would probably be seven to 10 days.

That period would be seen as an expression of good faith on the part of the militants. Once it was over, a more formal U.S.-Taliban agreement could be signed within days. The agreement would include the start of direct talks between the Taliban and the Afghan government next month, and the beginning of a U.S. troop withdrawal.

A U.S. official briefed on the calls confirmed that President Donald Trump has preliminarily approved the signing of a peace deal if the Taliban’s proposal to reduce violence is judged to have worked.

Abdullah tweeted that Pompeo had “expressed optimism that a reduction in violence and progress with current talks could lead to an agreement that would pave the way for intra-Afghan talks leading to durable peace.”

The State Department, in a statement, said “U.S. talks with the Taliban in Doha continue around the specifics of a reduction in violence.”

One person knowledgeable about the negotiations cautioned that it remains unclear what the status of any signed U.S.-Taliban agreement would be if violence resumed after the agreed reduction period, or if promised talks between the militants and the Afghan government did not succeed or even begin. This person and others spoke on the condition of anonymity about the closed-door negotiations.

In September, U.S. negotiator Zalmay Khalilzad announced that a tentative deal had been reached with the Taliban. Trump said he planned to bring Taliban leaders to Camp David to sign it, but he called off the meeting – which the Taliban later said it had not agreed to – as well as further talks, after the militants took credit for an attack in Kabul that killed an American soldier.

The draft agreed to at the time included Taliban cooperation in fighting against terrorist groups in Afghanistan, such as the Islamic State, as well as U.S. withdrawal and inter-Afghan talks, with a nationwide cease-fire at the top of the agenda. Trump announced in November that the talks had restarted, but progress was reported to be limited until recently.

Khalilzad met with Ghani in Kabul on Saturday to brief him on recent discussions with the militants and meetings with Pakistani officials, Ghani’s office said.

“We are waiting for a clear answer from the Taliban for a cease-fire or lasting reduction in violence based on a working mechanism which is acceptable to the people of Afghanistan and the U.S. government,” his office said.

In last week’s State of the Union address, Trump said that “the determination and valor of our warfighters has allowed us to make tremendous progress,” although U.S. government reports have indicated that the number of Taliban attacks during the last quarter of 2019 were the highest in nearly a decade.

But Trump, who has promised to stop the country’s “endless wars,” said that “peace talks are now underway” and “we are working to finally end America’s longest war and bring our troops back home.”

Tentative terms for a new U.S.-Taliban agreement are said to be nearly identical to the one in September. It was unclear, however, whether any initial withdrawal would reduce the U.S. force from about 12,000 to the 8,600 already planned without any deal or even lower.

The composition of an Afghan government negotiating team – one of the sticking points of the earlier agreement – also remains uncertain. Afghan officials announced in December that Ghani had won reelection with just over 50% in a nationwide September vote, avoiding a second round of voting.

But Abdullah, his estranged governing partner and main opponent, challenged the results.