LEBANON, N.H. (Reuters) - Democratic U.S. Senator Cory Booker all but guaranteed at a campaign event on Friday that he will pick a woman as his running mate if he wins his party’s nomination for president next year.

Democratic 2020 U.S. presidential candidate and U.S. Senator Cory Booker (D-NJ) gives the keynote speech at Brown Chapel AME Church in Selma, Alabama, U.S. March 3, 2019. REUTERS/Chris Aluka Berry

“I am very confident that this election, we will make history, because no matter what - I’m looking you in the eye when I say this - there will be a woman on the ticket,” he told a voter at a pub in Lebanon, New Hampshire, after she noted there has never been a female U.S. president or vice president.

“I don’t know if it’s the vice president’s position or the president’s position,” he continued. “If I have my way, there will be a woman on the ticket.”

The crowded Democratic field includes several prominent women, including four sitting U.S. senators: Kamala Harris of California, Elizabeth Warren of Massachusetts, Amy Klobuchar of Minnesota and Kirsten Gillibrand of New York.

When asked after the event whether he was promising his vice presidential candidate would be a woman, the New Jersey senator said, “Should I be a nominee, you can be sure that I’ll look to have gender diversity on my ticket.”

In 1984, Walter Mondale chose New York Representative Geraldine Ferraro as the first woman vice presidential candidate on a major party ticket.

Booker emphasized that he campaigned for Hillary Clinton in 2016, when she lost the presidency to Republican Donald Trump, and noted most of his senior staff positions, including his chief of staff and legislative director, are occupied by women.

Booker’s remarks on Friday appeared to go further than his comments last month, when he told MSNBC he would “be looking to women first” but said he did not want to “box himself in” so early in the election cycle.

Women voters and candidates helped power the Democratic wave that recaptured the U.S. House of Representatives in last fall’s elections, fueled in part by anger over Trump’s 2016 election despite multiple sexual misconduct allegations, which he denies.

If elected in November 2020, Booker would be the second black man to serve as president, after Barack Obama.

After the event, Booker also confirmed for the first time his relationship with actress Rosario Dawson, a day after Dawson told TMZ that their rumored romance was the real deal.

“I am dating Rosario Dawson, and I’m very happy about it,” said Booker.