KABUL/PESHAWAR, PAKISTAN: The Taliban said on Wednesday a plan from the Afghan president to stagger the release of Taliban prisoners violated an accord they struck with the United States and they would not talk with the Afghan government until all 5,000 prisoners were freed.

A Feb 29 pact between the Taliban and the United States has cleared with way for the withdrawal of US-led international forces after more than 18 years of war, but peace has to be negotiated between the militants and the US-backed government.

The Taliban have promised to open talks with the government as part of the accord but say the release of their 5,000 comrades held by the government was also part of the deal, and they won't talk until all are freed.

President Ashraf Ghani has declined to release all 5,000 in one go. Instead, he has ordered the release of an initial 1,500, with the other 3,500 to be set free in parallel with progress in the peace talks.

"We never agreed to any conditional release of prisoners," Suhail Shaheen, spokesman for the Taliban based in Doha, told Reuters by phone.

"If someone claims this, it will be against the peace accord that we signed on February 29.”

The main element of the US withdrawal agreement is a Taliban promise that they will not let Afghanistan be used by terrorists to attack the United States and its allies.

The pact will let US President Donald Trump fulfil his promise to end the war and bring all of the troops home within 14 months.

The release of the prisoners - including some 1,000 government troops held by the militants - is meant to be a confidence-building measure to pave the way for the so-called intra-Afghan talks.

The conflicting positions on the issue between the Taliban and Ghani's government appears to stem from different wording in documents exchanged between the United States and the Taliban on the one hand, and the United States and government on the other.

“It is properly explained in the peace accord that first 5,000 prisoners would be freed and then the Afghan dialogue would be initiated," Shaheen said.

Zalmay Khalilzad, the US special envoy who was the key negotiator in talks with the Taliban, has urged both sides to sit down for talks on the problem.

Despite the accord between the United States and the Taliban, fighting has continued in various parts of the country.

Taliban leaders have told Reuters that their leadership council has rejected an Afghan government demand that they issue written guarantees to stop fighting.

A senior Afghan government official told Reuters that the government position as set out by Ghani would not change.

"It is not practical for us to release all 5,000 at once without a Taliban commitment for direct negotiations and a significant reduction in violence," said the official, who declined to be identified.

The government's decision to release the 1,500 prisoners was a gesture of good faith and the Taliban should reciprocate, the official said.