Trump's lawyers said in Monday's filing that the president denies "these unfounded accusations" and was prepared to show that they were "false, legally insufficient and made in a transparent politically-motivated attack." They said the allegations have been disputed even by a member of Zervos' family.
Zervos was among several women who made sexual allegations against Trump when he was the Republican nominee during the presidential race last year. Trump has strenuously denied their allegations.
After appearing on Trump's show, Zervos said she later asked him for a job. She said they met and he kissed her on the lips and asked for her phone number. She said at a later meeting at a California hotel he became sexually aggressive, kissing her and touching her breasts.
During the presidential campaign, a tape of Trump talking about fame enabling him to grope and try to have sex with women emerged. On the 2005 "Access Hollywood" tape, Trump says when he's attracted to beautiful women "I just start kissing them. It's like a magnet." He says when you're a star, women let you.
"Grab them by the p----," Trump adds. "You can do anything."
Trump later said in a presidential debate that he never did any of the actions heard on the tape, which he described as locker room talk.
Trump's wife, Melania Trump, blamed Access Hollywood host Billy Bush for what Trump said. She said they were involved in "boy talk, and he was led on, like egged on, from the host to say dirty and bad stuff."
A Zervos attorney, Gloria Allred, said she doesn't believe the president of the United States enjoys legal immunity from a defamation lawsuit. She said the Supreme Court addressed the legal immunity issue in a case involving Democratic President Bill Clinton and "determined unanimously that no man is above the law, and that includes the president of the United States."
"We look forward," she said, "to arguing this issue in court."