Former U.S. First Lady Michelle Obama on Monday evening took aim at President Donald Trump for his refusal to concede after losing the Nov. 3, presidential election.

In an Instagram post, Mrs Obama said the love of country required everyone to respect election results even when unfavorable.

She wrote: “The presidency doesn’t belong to any one individual or any one party.

“To pretend that it does, to play along with these groundless conspiracy theories, whether for personal or political gain, is to put our country’s health and security in danger.

“This isn’t a game.

“So I want to urge all Americans, especially our nation’s leaders, regardless of party, to honour the electoral process and do your part to encourage a smooth transition of power, just as sitting presidents have done throughout our history.”

The former First Lady recalled her struggle after Trump defeated Hillary Clinton “by a far closer margin” in the 2016 presidential election.

Mrs Obama said although she and her husband were hurt and disappointed, they listened to the voice of the people and immediately set the transition ball rolling.

“The American people had spoken. And one of the great responsibilities of the presidency is to listen when they do.

“So, my husband and I instructed our staff members to do what George and Laura Bush had done for us: run a respectful, seamless transition of power – one of the hallmarks of American democracy.

“We invited the folks from the president-elect’s team into our offices and prepared detailed memos for them, offering what we’d learned over the past eight years.

“I have to be honest and say that none of this was easy for me,” she said.

Mrs Obama further wrote that Trump had “spread racist lies” about her husband that had exposed her family to danger.

It was not something she was ready to forgive, according to her, but she mustered the strength and maturity to let go for the sake of the country.

“So, I welcomed Melania Trump into the White House and talked with her about my experience, answering every question she had, from the heightened scrutiny that comes with being First Lady to what it’s like to raise kids in the White House.

“I knew in my heart it was the right thing to do, because our democracy is so much bigger than anybody’s ego,” she disclosed.

The 2020 election was called in favour of former Vice President Joe Biden on Nov. 7, after crossing the 270 electoral college votes required to win the race.

But Trump, who has refused to concede, is claiming that the votes were rigged against him.

The president, who is challenging the election in court in key battleground states, is impeding a smooth transition of power to Biden. (NAN)