Ivanka Trump, daughter and adviser to the US president, has told a Tokyo summit that sexual harassment of women should "never be tolerated".
She also called for boosting equal participation in "traditionally male-dominated sectors of our economy".
Officials blamed the many empty seats in the hall on security restrictions.
Ms Trump's father has been accused by multiple women of sexual harassment and assault, all of which his representatives have denied.
Accusations of groping, forced kissing, and walking unannounced into changing areas at beauty pageants were made against Donald Trump when he was running for president.
Past weeks have brought heightened focus on sexual harassment around the world, which was sparked by the accusations against Hollywood movie mogul Harvey Weinstein, continued in the #metoo movement where victims shared stories online, and has already claimed the job of a UK cabinet minister, Michael Fallon.
When asked last week about the claims against Mr Trump, White House press secretary Sarah Sanders said all the women who made accusations against Mr Trump were lying.
At the World Assembly for Women in Tokyo, Ms Trump said: "All too often, our workplace culture fails to treat women with appropriate respect.
"This takes many forms, including harassment, which can never be tolerated," she added.
She urged the world should boost women participation in the so-called STEM fields - science, technology, engineering and maths.
And she pointed out that men are not referred to as "working men" in the same way women are called "working women".
"It is my hope that by the time my daughter Arabella grows into a woman, she will not be defined by whether she works inside or outside the home," she said.
Her speech in Tokyo comes days before her father's first trip to Asia since taking office.
A Washington post reporter at the event tweeted a picture of empty rows of seats.
This is what the hall in Tokyo looked like as Ivanka Trump gave her speech at a Japanese government women’s conference pic.twitter.com/7IzXMpxa6b— Anna Fifield (@annafifield) November 3, 2017
Reports said officials had blamed tight security restrictions, but there were no reports of long queues.
Speaking at the same summit, Japanese Prime Minister Shinzo Abe said his government was also trying to bring more women into the workforce.
"We've put our full strength into creating an environment where it's easy for women to work," Mr Abe said in his opening address.
Despite these efforts, however, Japan's gender gap remains wide. The country ranked 114 out of 144 in the World Economic Forum's 2017 Global Gender Gap report, which was released as Ms Trump prepared to speak.
Working as an adviser to her father, Ms Trump has made women's issues one of her key policy areas since joining the White House.
Her trip to Japan is also to lay the groundwork for her father's trip, which begins in Japan on Sunday.