New Zealand actress Lucy Lawless says the now US President Donald Trump "crossed a line" when he asked her out for a date back in 1997.

Appearing on Seven Sharp to promote her upcoming animated movie Mosley, Lawless was asked by Jeremy Wells about the time Trump made advances towards her.

"It was so weird, he rang me up when I was staying in his hotel after I just got engaged to my husband," she explained.

"My phone rings at the Trump Tower and it's Donald Trump and he asks me out and I say, 'no sorry I just got engaged'.

"He was fine about it, I'm not sure how much he cared, he'd seen me in the lobby doing some press earlier and he didn't pay any attention to me and walked away, but I got the call later that day."

The Xena Warrior Princess actress then recounted how looking back on the incident it was "a bit creepy".

"I thought what was wrong with this interaction and my friend said 'because he used the guest list of his hotel as his dating pool.'"

"I thought yes, it crossed a line, why do I feel really a little creeped out by that."

Lawless explained that Trump himself wasn't "irksome himself" it was just a "slightly creepy" use of the guest list in his hotel.