US President Donald Trump has defended his daughter Ivanka after she took his place at a meeting of G20 world leaders in Germany at the weekend.

The move raised eyebrows worldwide and drew a sharp rebuke from Chelsea Clinton, the daughter of Bill and Hillary, who was drawn into the fray by Mr Trump.

“If Chelsea Clinton were asked to hold the seat for her mother, as her mother gave our country away, the Fake News would say CHELSEA FOR PRES!” he tweeted on Monday (US time).

Chelsea Clinton hit back on Twitter: “Good morning Mr. President. It would never have occurred to my mother or my father to ask me. Were you giving our country away? Hoping not.”

Ms Trump, a White House adviser, sat briefly in her father’s chair on Saturday at the Group of 20 summit meeting in Hamburg, Germany, during a closed-door session on African development, addressed by Jim Yong Kim, the president of the World Bank.

Her appearance unleashed a Twitter storm and caught the attention of the German media and several other outlets.

In a separate tweet, Mr Trump called the arrangement “very standard” and noted that German Chancellor Angela Merkel, who was hosting the G20 summit, agreed.

Good morning Mr. President. It would never have occurred to my mother or my father to ask me. Were you giving our country away? Hoping not. https://t.co/4ODjWZUp0c

— Chelsea Clinton (@ChelseaClinton) July 10, 2017

Ms Merkel had dismissed the move at a news briefing after the summit.

“Ivanka belongs to the US delegation,” said Ms Merkel, who has worked with the President’s daughter on various issues.

Nikki Haley, the US ambassador to the United Nations, also defended Ms Trump’s presence, saying on Sunday that the President’s daughter had often sat in on meetings with her and Mr Trump, especially those regarding women and business.

The move comes only weeks after a bizarre television interview in which Ms Trump said she tried to “stay out of politics”, despite her key White House role.

Appearing on conservative talk show Fox and Friends in late June, Ms Trump appeared to give mixed messages about her role.

“I don’t profess to be a political savant so I leave the politics to other people and really lean into the issues that I care deeply about,” Ms Trump told host Aisnley Earhardt at the time.

Ms Trump ran a clothing and jewellery business before taking a formal job at the White House after her father took office in January and has adopted women’s issues as a signature policy area.

At the G20, she also appeared at a separate event alongside World Bank president Mr Kim for a public-private loan program aimed at boosting female entrepreneurs in developing countries.

Lawrence Summers, a former World Bank official and economic adviser under former Democratic president Barack Obama, said it was rare for government heads to leave during major summits and that, when they must, foreign ministers or other very senior government officials normally fill in.

“There is no precedent for a head of government’s adult child taking a seat,” he wrote in the Washington Post.

“There is no precedent for good reason. It was insulting to the others present and sent a signal of disempowerment regarding senior government officials.”

– with AAP