The US military has handed control of a controversial prison housing more than 3,000 Taliban fighters and terrorism suspects to the Afghan authorities.
In a small ceremony, Afghan officials said inmates had been transferred to their authority.
The move is part of a deal to transfer all Afghan prisons back to local control ahead of the withdrawal of Nato forces at the end of 2014.
Bagram prison has been at the centre of a number of prisoner abuse allegations.
Although Afghan President Hamid Karzai has hailed the handover, disagreements with the US remain.
Washington is insisting that it will maintain control over some detainees in the prison.
Meanwhile, a new report suggests that some Taliban are open to a general ceasefire or political agreement allowing for a continuing US military presence after 2014.
'Glorious ceremony'
The handover took place at a brief ceremony which correspondents say was poorly attended by US and Nato officers.
But for the Americans there are issues of trust. Even as the official handover ceremony takes place, there are still deep divisions. At the crux of the disagreement is the US insistence that it retains the right to arrest and hold prisoners caught "on the battlefield".
While about 3,000 prisoners have already been transferred, the US is still believed to be holding on to hundreds of others and around 50 nationals from "third countries", such as Pakistan. Among US concerns are what would happen to "high-value detainees" once handed over to the Afghans - could they be released?
But human rights groups and some Afghans are worried that continued US control of part of the prison could lead to the creations of "Guantanamo's twin brother".
"We transferred more than 3,000 Afghan detainees into your custody... and ensured that those who would threaten the partnership of Afghanistan and coalition forces will not return to the battlefield," said Col Robert Taradash, the only US official at the ceremony.
"Our Afghan security forces are well trained and we are happy that today they are exercising their capability in taking the responsibility of prisoners independently and guarding the prisoners," said acting Defence Minister Enayatullah Nazari.
"We are taking the responsibility from foreign forces."
AFP news agency photos showed a small group of inmates being released as part of the ceremony.
Now officially known as the Parwan Detention Centre, Bagram prison lies about 40km (25 miles) north of the capital, Kabul.
It was once located in one of the largest military bases for Nato-led forces in Afghanistan, but the new Parwan facility was constructed a few miles away and populated with inmates in 2010.
The US military still wants to run a section of the jail and is not handing over hundreds of detainees, saying it has the right to hold insurgents caught on the battlefield, the BBC's Jonathan Beale in Kabul reports.
Director of Centre for Conflict and Peace Studies: "The transfer is a positive step but there are many obstacles that still need to be addressed"
These include about 50 foreigners not covered by the handover agreement signed in March.
Privately, the US is concerned that some high-value inmates could be released if they are handed over, our correspondent says.
That has angered the Afghan president, who says that full Afghan control is an issue of sovereignty.
According to Afghan officials, there is a dispute over 34 inmates in particular, but they say they have made it clear they do not want control over the foreign prisoners.
Meanwhile the director of the Centre for Conflict and Peace Studies, Hekmat Karzai, told the BBC that the Americans believed they had a strategic interest in keeping these detainees.
"The argument is that while they have troops on the ground it's very difficult to release these people," said Mr Karzai, who is a cousin of the Afghan president.
In January 2012, Afghan investigators accused the US Army of abusing detainees at Bagram.
The investigators said prisoners had reported being tortured, held without evidence and subjected to humiliating body searches.
Nato and the US have rejected allegations of abuse as untrue and pointed to the fact that they have given the Afghan Human Rights commission access to check them independently.
In February this year, US soldiers unwittingly burned Korans confiscated from prisoners at Bagram, leading to days of protests and targeted killings across Afghanistan. A US investigation said there was no malicious intent to disrespect Islam.
Separately, a new report has suggested some Taliban may be open to a continuing US military presence after 2014, as long as the role is strictly defined.
Comment and viewpoint:
It was not enough to fly in with missiles, ground force, air force and the full ground patrol...Oh no, kill the masses, ally with the neighbours in a quest to massacre the people, take control of the gas pipelines; set up a prison; extradite humans without the court of law to animal sheltered prisons, namely Guantanamo, organise rendition flights from Bagram to the US to receive innocent victims (Aafia Siddiqui) and imprison her for life without a fair trial. Then continue to cause anarchy in a country and always blame the Taliban who you funded to fight the Soviet Union, then arrest the indigenous people and place them in the lawless prison, Bagram and now commission the Afghani's to do the job for you...except you are not planning to leave the country; are you?......And we are supposed to be grateful?
The Muslim world has woken up to the pattern of US/Britain/France foreign policy. Brutal force did not work to reform the people away from Islam, though it secured economical interests for the US and Britain in Iraq and Afghanistan. Now, across the Muslim world they sugar coat their intentions and discuss how they wish to remove troops from the region and allow the people to determine their future. Unfortunately whether the US or Britain use a unilateral stance or a multilateral stance the intentions of Western foreign policy remains the same. To maintain dominance over the Muslim world and to ensure Islam does not become a political force to be reckoned with. For this reason Tony Blair in his proposal to the nation (published in the Evening Standard) is quoted to have called for 'evolution' in the Middle East rather than 'revolution'. This reveals an underlying idea always maintained in the West. Ultimately, the Muslim world will remain a battle ground for the West militarily, politically, and intellectually until we leave our way. So what we need to do is stick to our way, and advocate Islam as a true solution for the Muslim world.
As we wake up to the mega colonialist plan, we hope that the believers will defeat the colonialist plan and one day triumph again where peace and prosperity can be brought to Muslims and non-Muslims alike.
Allah (swt) reminds us in the Qur'an "And never will Allah grant to the disbelievers a way (to triumph) over the believers" [TMQ An-Nisa: 141].
