UNITED NATIONS (AFP, REUTERS) - Chinese President Xi Jinping pressed on Sunday (Sept 27) for the world to step up efforts to improve women's rights, but his push was clouded by his own country's detention of feminists as United States presidential hopeful Hillary Clinton called his efforts "shameless".

Paying his first visit to the United Nations, Mr Xi invited fellow world leaders to a special session to mark 20 years since a landmark UN conference on women in Beijing.

He announced a US$10 million (S$14 million) pledge to the UN agency for women and said China would in the next five years build 100 health centres and an equal number of school start-ups for girls in the developing world.

"China will do more to enhance gender equality as its basic state policy," he said, citing a Chinese proverb that women "hold up half the sky". He added: "In many parts of the world... inequality still exists between men and women in rights, opportunities and access to resources."

The 1995 conference declared that "women's rights are human rights" and called for women's full incorporation in schools and government.

China earlier this year detained for one month five young feminists on the eve of International Women's Day.

China, which clamps down on any sign of domestic dissent, rounded up the women as they prepared to hand out leaflets about sexual harassment on public transport.

Ahead of Sunday's UN meeting, the five women said in a letter: "We sincerely hope.. President Xi can lead by example." China has also faced international criticism for effectively placing Ms Liu Xia, the wife of jailed Chinese Nobel Peace Prize laureate Liu Xiaobo, under house arrest since 2010.

US President Barack Obama shunned Mr Xi's meeting, instead issuing a statement vowing to "work tirelessly" for a world in which "every woman and girl can enjoy the rights and freedoms that are her birthright".

Mrs Hillary Clinton, who is campaigning to succeed Mr Obama and become the first female US president, condemned Mr Xi and voiced support for the #FreeThe20 campaign that aims to release 20 women activists around the world.

"Xi hosting a meeting on women's rights at the UN while persecuting feminists? Shameless," Mrs Clinton wrote on Twitter.

As US first lady, Mrs Clinton gave a speech at the 1995 Beijing conference that was considered influential in bringing a woman's role in society to the level of a fundamental universal right.

But as Mr Obama's Secretary of State, she also sought a smooth relationship with China and faced criticism from some human rights activists.

Mr Xi has been seeking to highlight China's growing global role.

He pledged US$2 billion in development aid on Saturday and a day earlier announced greater action on climate change as Mr Obama welcomed him at the White House.

A wide range of national leaders spoke at Mr Xi's event, including women such as German Chancellor Angela Merkel, Brazilian President Dilma Rousseff, Bangladeshi Prime Minister Sheikh Hasina and Liberian President Ellen Johnson Sirleaf.

Dr Merkel, who has championed a welcoming approach to refugees, said it was particularly critical to protect women facing rape, slavery and other abuses in Syria, Iraq, Nigeria and other troubled countries.

"Women's rights are human rights, too. Isn't it disgraceful to humanity that we need to underline this?" she said.

"But it is true - women urgently need more protection, particularly in war zones and crisis regions," she said.

Civil society under threat in China

In an open letter to UN Secretary-General Ban Ki Moon, who joined Mr Xi, the five formerly detained feminists said that at home China was increasingly stifling civil society.

"This is an unexpected and shameful setback, as well as a historical mistake" 20 years after the Beijing conference, they wrote.

China's record on women's rights is hardly the worst in the world, with the communist leadership considering gender equality a key principle.

Some 23 per cent of national legislators in China are women, compared with 19 per cent in the US Congress, according to the World Bank. The highest is 64 per cent in Rwanda, where women form a majority in the wake of the 1994 genocide.

The United States, meanwhile, is one of the main countries holding out from ratifying the UN treaty on women's rights, in part due to conservative lawmakers' objections to its enshrinement of women's reproductive rights.