(CNN)US forces on Saturday rescued an American citizen taken hostage by armed men earlier this week in Niger and held in northern Nigeria, the Pentagon said.

"U.S. forces conducted a hostage rescue operation during the early hours of 31 October in Northern Nigeria to recover an American citizen held hostage by a group of armed men. This American citizen is safe and is now in the care of the U.S. Department of State. No U.S military personnel were injured during the operation," Pentagon spokesman Jonathan Hoffman said in a statement.

"We appreciate the support of our international partners in conducting this operation. The United States will continue to protect our people and our interests anywhere in the world."

The mission, which was several hours long, was conducted by the Navy's elite SEAL Team 6 who were flown to the region by Air Force special operations, a US official with knowledge of the operation told CNN.

The US forces who conducted the mission killed six of the seven captors, the official said. The US believes the captors have no known affiliation with any terror groups operating in the region, and were more likely bandits seeking money.

The State Department confirmed earlier this week that a US citizen had been abducted in Niger.

Local media outlets reported that the US citizen was a male missionary. CNN has not been able to confirm the citizen's identity.

The governor of the local region where the abduction took place was quoted in various local media and by French media reporting from Niger as saying that six men on motorbikes armed with AK-47s came to the man's property in the village of Massalata, close to the border with Nigeria.

The governor, Abdourahamane Moussa, told these media outlets that after demanding money, the men took the American citizen with them in the direction of the Nigerian border.

The State Department spokesman said that "when a U.S. citizen is missing, we work closely with local authorities as they carry out their search efforts, and we share information with families however we can."

On Saturday, US Secretary of State Mike Pompeo said the US citizen would be reunited with his family.

"Thanks to the extraordinary courage and capabilities of our military, the support of our intelligence professionals, and our diplomatic efforts, the hostage will be reunited with his family," Pompeo said in a statement. "We will never abandon any American taken hostage."

The first lady was escorted by the masked military man and sheltered under an umbrella with him during the visit to Arlington National Cemetery, on Donald Trump 's first public engagement since the election was called for Joe Biden .

Neither Melania, 50, nor the president, 74, were wearing masks at the cemetery, unlike Donald Trump's daughter Ivanka who had a face covering on.

Escorted: Melania Trump takes the hand of a uniformed member of the US armed forces during Wednesday's wreath-laying ceremony, leaving Donald Trump to walk by himself

Melania sheltered under an umbrella during the visit to Arlington National Cemetery on a wet, dreary Veterans Day on Wednesday

Donald Trump walked alone during his first public engagement since the presidential election was called in favor of Democrat Joe Biden on Saturday

One former Trump aide, Omarosa Manigault Newman, has spread rumours that the couple's marriage could end in divorce when their term in the White House ends in January.

She claimed: 'Melania is counting every minute until he is out of office and she can divorce.

'If Melania were to try to pull the ultimate humiliation and leave while he's in office, he would find a way to punish her.'

Close watchers of the couple noticed at the end of a debate last month that Melania appeared to yank her hand away from her husband as they walked off a stage.

The Trump family attracted criticism during the first debate in Cleveland for failing to wear masks while sitting in the audience.

Melania had appealed as long ago as April for people to wear masks, long before Donald Trump was first pictured wearing a face covering.

The presidential couple walked separately from each other as they took part in the somber ceremony at the tomb of the unknown soldier in Arlington's National Cemetery

Melania Trump, pictured, was not wearing a mask despite appealing as long ago as April for people to wear face coverings during the pandemic

After joining her husband on stage without a mask after the first debate in Cleveland, Melania did wear a mask at the end of the final head-to-head in Nashville.

But on Wednesday, Melania was again without a mask despite her close proximity to the military man escorting her.

Neither Donald nor Melania made any public remarks during the somber ceremony on a wet, dreary day in Washington, although Melania paid tribute to the nation's troops on Twitter.

Melania had three days earlier echoed her husband's efforts to undermine the election by suggesting that 'illegal' votes had been cast.

The first lady said on Sunday that 'the American people deserve fair elections... every legal - not illegal - vote should be counted'.

The president, who during the campaign refused to commit to honoring the result, has falsely claimed that he would win the election but for 'illegal' votes.

Spectators look on as the president and first lady arrive for the rainy wreath-laying ceremony

Donald Trump lays a wreath on his first official outing from the White House since Joe Biden's victory in the election was declared on Saturday

Ivanka Trump was wearing a mask at Wednesday's ceremony, unlike the president or first lady

Vice president Mike Pence also attended the Veterans Day ceremony, while president-elect Biden appeared at the Korean War Memorial in Philadelphia.

While Trump's official schedule has been limited in recent days, he has made significant personnel moves, including the firing of defense secretary Mark Esper.

His pick as acting defense secretary, Christopher Miller, was among the Pentagon brass that joined him at Arlington.

Trump has not addressed the nation since Biden's win, but has spread unfounded claims on Twitter and refused to acknowledge that his term is nearing its end.

He has made no mention of the dramatic rebound in the Covid-19 pandemic across the country, which is now seeing more than 100,000 infections per day.

Some supporters pushed back against the notion that Trump is shirking his presidential duties.

President-elect Joe Biden and incoming first lady Jill Biden made their own appearance at a Korean War memorial in Philadelphia

'The president is out there as much as he's ever been on Twitter, and the White House team are moving ahead with budget and staffing priorities,' said Dan Eberhart, a prominent Republican donor and Trump backer.

He added: 'The president is understandably focused on the ballot counting, but at some point soon he needs to turn his attention back to the lame duck session and putting a capstone on his first four years.'

Aides claim that Trump has been calmer than his tweets suggest, suggesting that he wants to keep fighting almost as performance, as a show to the 70million people who voted for him.

In recent days, some aides, including his daughter Ivanka, have started to talk to him about an endgame, questioning how much longer he wants to fight the result.

While Georgia is heading for a recount and Arizona is still too close to call, Biden's win in Pennsylvania means he already has more than the 270 electoral votes needed.

The Democrat now leads by more than 50,000 votes in the state, which narrowly voted for Trump over Hillary Clinton in 2016.