Washington: The first lady of the United States, Melania Trump, has responded to a widely-watched interview with adult-film star Stormy Daniels who claims she had a sexual encounter with President Donald Trump.

Asked whether Melania Trump watched the 60 Minutes interview on Sunday night, local time, her spokeswoman told MSNBC: "She's focused on being a mom and is quite enjoying spring break at Mar-a-Lago while working on future projects."

It came as Donald Trump's personal lawyer Michael Cohen demanded that Daniels "cease and desist" after she spoke about her alleged affair with Trump, the non-disclosure agreement she signed and the threat she said she received to stay silent.

Fox reported that Cohen's attorney demanded in a letter, sent late on Sunday after the interview was broadcast, that Daniels, whose real name is Stephanie Clifford, apologise for implying in the interview that Cohen was behind a threat she said a stranger made against her in 2011 if she did not "leave Trump alone."