US President Joe Biden and first lady Jill Biden joined grieving families at Dover Air Force Base on Friday to honour the three American service members killed in a drone attack in Jordan.

The solemn ritual, called a dignified transfer, has become relatively uncommon in recent years as the US has withdrawn from conflicts abroad.

The Bidens arrived at the base on Friday to witness the transfer of the remains of the troops killed in Sunday’s attack.

Defence secretary Lloyd Austin and General CQ Brown, chairman of the Joint Chiefs of Staff, joined the Bidens for the transfer in Dover.

The Bidens met the families privately before the ceremony.

The service members killed on Sunday were all from Georgia, Sgt William Jerome Rivers, 46, Sgt Kennedy Sanders, 24, and Sgt Breonna Moffett, 23. Sanders and Moffett were posthumously promoted to sergeant rank.

The deaths were the first US fatalities blamed on Iran-backed militia groups, who for months have been intensifying their attacks on American forces in the region following the onset of the Israel-Hamas war in October.

Separately, two Navy Seals died in a January mission to board an unflagged ship that was carrying illicit Iranian-made weapons to Yemen.

“These service members embodied the very best of our nation, unwavering in their bravery. Unflinching in their duty. Unbending in their commitment to our country, risking their own safety for the safety of their fellow Americans, and our allies and partners with whom we stand in the fight against terrorism,” Mr Biden said earlier this week.

“It is a fight we will not cease.”

At Thursday’s National Prayer Breakfast at the Capitol, Mr Biden acknowledged the service members by name, again vowing to never forget their sacrifice to the nation.

“They risked it all,” the president said.

Friday is the second dignified transfer Mr Biden has attended as president. In August 2021, he took part in the ritual for the 13 service members killed during the suicide bombing in Kabul.

The US government said this week that the Islamic Resistance in Iraq, an umbrella group of Iran-backed militias that includes the group Kataib Hezbollah, had planned, resourced and facilitated the overnight drone attack.

More than 40 troops were also injured in the Sunday at Tower 22, a secretive US military desert outpost whose location allows US forces to infiltrate and quietly leave Syria.