An American navy veteran detained in Afghanistan since 2020 was released in exchange for a Taliban ally imprisoned in the United States for heroin smuggling, US and Afghan officials announced on Monday.

The Taliban government freed Mark Frerichs, who was working as a civil engineer on construction projects in Afghanistan when he was detained 31 months ago.

The US government, meanwhile, released Bashar Noorzai, a former regional strongman who was sentenced to life imprisonment in an American court 17 years ago for smuggling large amounts of heroin.

"After long negotiations, US citizen Mark Frerichs was handed over to an American delegation and that delegation handed over (Noorzai) to us today at Kabul airport," Afghan Foreign Minister Amir Khan Muttaqi said at a press conference.

"We are happy that at Kabul International Airport, in the capital of Afghanistan, we witnessed the wonderful ceremony of one of our compatriots returning home."

Frerichs, meanwhile, flew to Qatar, a US official said, adding that he was "in stable health."

"Today, we have secured the release of Mark Frerichs, and he will soon be home," US President Joe Biden said in a statement.

"Bringing the negotiations that led to Mark's freedom to a successful resolution required difficult decisions, which I did not take lightly," he said.

Qatari officials confirmed they played a months-long role in securing the veteran's freedom.

The US government gave no other details, but diplomats told AFP that Qatar had helped US officials step up contacts with the Taliban in the months after Washington withdrew from Afghanistan. "This is one result of those contacts," a diplomat said. (AFP)