Ivanka Trump has broken with protocol and briefly taken her father US President Donald Trump's seat at the G20 leaders' summit in Hamburg.

Key points: Ivanka Trump took her father's seat for a brief period of time when the head of the World Bank spoke to the G20

Ivanka Trump took her father's seat for a brief period of time when the head of the World Bank spoke to the G20 Ms Trump is a senior adviser, but absences are usually covered by high-ranking state officials

Ms Trump is a senior adviser, but absences are usually covered by high-ranking state officials Ms Trump also launched the Women Entrepreneurs Finance Initiative with the World Bank Group president earlier in the day.

The US President had stepped away for a meeting with Indonesian President Joko Widodo when Ms Trump, officially an adviser to the President, took the seat between British Prime Minister Theresa May and Chinese President Xi Jinping.

Absences at the G20 are usually covered by high-ranking state officials. The President returned a short while later.

A White House official said Ms Trump, a senior adviser, moved forward from the back of the room when the head of the World Bank discussed topics particularly relevant to her.

A photograph of the "first daughter" was tweeted by a member of the Russian delegation, before the tweet was deleted.

Svetlana Lukash's tweet shows Ivanka Trump replacing the President at G20 summit. ( Supplied )

First lady Melania Trump also had a notable G20 role — she was spotted at more than one of the President's bilateral meetings.

Jared Kushner, Ivanka Trump's husband and a senior adviser, also was present in a number of the President's meetings.

It is all part of Mr Trump's family-focused governing style that takes its cues from his decades running a family business.

The first lady was rarely seen or heard from during the early months of her husband's administration. But during the President's first two trips abroad, she has taken on a far more prominent role.

"It's not uncommon for the President to ask Mrs Trump to be present for many different meetings," Mrs Trump's spokeswoman, Stephanie Grisham, said.

Many members of the Trump family have accompanied Mr Trump on his diplomatic trips abroad. ( Facebook: Donald J Trump )

Trump praises daughter at initiative launch

Earlier Ms Trump also headlined her own event at the G20 when she joined World Bank Group President Jim Yong Kim to launch the Women Entrepreneurs Finance Initiative.

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The World Bank fund conceived by the US President's 35-year-old daughter aims to help women entrepreneurs access capital and other support and received a $US50 million ($65 million) contribution from the United States.

Mr Kim said the fund had raised more than $US325 million ($427 million) so far for projects and programs to support women and women-led businesses by improving access to capital and markets, providing technical assistance, training and mentoring, and pushing public policy.

The fund grew out of conversations between Ms Trump and Mr Kim early in Mr Trump's administration.

"This is not a cute little project," Mr Kim said during a panel discussion, arguing the effort would spur real economic growth.

In addition to the US, the new fund has also received contributions from several countries including Australia.

Malcolm Turnbull and Theresa May attend the launch of an initiative co-founded by Ivanka. ( Twitter: Prime Minister's Office )

Officials have stressed that Ms Trump will not have an operational or fundraising role with the fund, which will be run by a governing committee of contributors.

Mr Trump said the fund would help eliminate barriers for women to launch businesses, help transform "millions and millions of lives" and "provide new hope to these women from countless communities all across the world".

The President has been criticised for crude remarks he has made about women over the years, including a recent tweet focusing on a television news host's appearance.

Mr Trump's senior staff is dominated by men, despite the considerable influence of Ms Trump.

During his 2016 campaign, Mr Trump frequently criticised rival Hillary Clinton's ties to her family's Clinton Foundation, which received millions in donations from Saudi Arabia, the United Arab Emirates and several other Mideast nations for charitable work.

Mr Trump also took the opportunity to praise his eldest daughter, saying he had been proud of her since "day one" and offered a rare, self-deprecating assessment of the challenges he has added to her life.

"If she weren't my daughter, it would be so much easier for her," he said.

"That might be the only bad thing she has going, if you want to know the truth."

Ms Trump has faced sustained criticism from opponents of her father who'd hoped she would be able to push him to adopt more moderate policies. Many have labelled her "complicit" in his agenda.

ABC/AP