Ailing Gillard misses Obama reception

Battling an upset stomach that forced her to withdraw from three official functions, the first full day of Prime Minister Julia Gillard's trip to New York has not gone to plan.

With the rich and powerful in reach, the Australian leader was left to nurse a troublesome tummy in her luxury hotel room, appearing in public only once today.

"It is expected she will resume a full schedule of engagements tomorrow," a spokesman said.

The sickness has already seen Ms Gillard miss key fixtures ahead of Tuesday's official opening of the United Nations Leaders Week, including a reception today for world leaders hosted by US President Barack Obama.

New York's midtown was shut down all day in preparation for the president's one-night stay in the city. He will stay at the same hotel as Ms Gillard, but the pair are unlikely to meet.

Foreign Minister Bob Carr, also in New York, said Ms Gillard took the right course of action to alter her schedule.

"You shouldn't be struggling to your feet," Senator Carr told reporters.

Earlier in the day more than 200 wealthy and influential business leaders gathered at the prestigious Pierre hotel to hear Ms Gillard, the guest speaker, promote Australia's strong economy in an increasingly diverse regional market.

An audience including billionaire businessman David H Koch and former US ambassador to Australia, Thomas Schieffer, instead heard from Senator Carr after Ms Gillard's eleventh-hour withdrawal.

"That's a bit of a let-down," said one Australian businessman, who asked not to be named, of Ms Gillard's absence.

"She's not my cup of tea, but she's who we came to see."

On Monday afternoon, the prime minister attended the launch of an international gender equality initiative alongside US Secretary of State Hillary Clinton.

Speaking briefly about Australia's commitment to boosting the role of women in society, Ms Gillard, who reminded the audience of her position as first female Australian prime minister, received hearty applause.

"In Australia, in the Pacific, in every corner of the world all women are created equal ... women and girls must have futures equal to those of their brothers and fathers," she said.

Dressed in blue, Ms Gillard sat through the 90-minute event on stage in front of a packed gallery, but later withdrew from another engagement.

Parliamentary Secretary for Foreign Affairs Richard Marles replaced Ms Gillard at the high-level meeting on the Rule of Law at UN headquarters.

"Julia Gillard is a very strong and feisty person," Mr Marles said.

"To be laid low by this means that she has had a pretty significant bout of tummy troubles."

Ms Gillard is to address the UN General Assembly on Wednesday and she has also planned a number of meetings with world leaders before her Thursday departure from the US.

A key aim of Ms Gillard's New York visit is to lobby Australia's bid for a permanent seat on the UN Security Council, which will be decided by way of secret ballot on October 18.

-AAP