GENEVA - Eight years after a U.S.-led invasion ousted the Taliban from power in Afghanistan, the war-ravaged state is the most dangerous place in the world for a child to be born, the United Nations said on Thursday.

It is especially dangerous for girls, the United Nations Children's Fund (UNICEF) said in launching its annual flagship report, The State of the World's Children.

Afghanistan has the highest infant mortality rate in the world -- 257 deaths per 1,000 live births, and 70 percent of the population lacks access to clean water, the agency said.

As Taliban insurgents increase their presence across the country, growing insecurity is also making it hard to carry out vital vaccination campaigns against polio, a crippling disease still endemic in the country, and measles that can kill children.

Afghanistan today is without a doubt the most dangerous place to be born, Daniel Toole, UNICEF regional director for South Asia, told a news briefing in Geneva.

A Taliban-led insurgency and militant attack on an international guest-house in Kabul that killed five U.N. foreign staff last month prompted the world body to evacuate hundreds of international staff from Afghanistan for several weeks.

Some 43 percent of the country is now virtually off-limits to aid agencies due to insecurity, according to Toole.

The Taliban have been building their forces in their traditional southern and eastern Afghanistan stronghold and are increasing attacks in the north and west. Teaching girls is one of the practices they forbid.

Some 317 schools in Afghanistan were attacked in the past year, killing 124 and wounding another 290, Toole said.

We have seen a drop in the number of children who are attending schools and particularly young girls, he added.

School enrollment in Afghanistan had risen to 5 million, including 2 million girls, against 1 million with virtually no girls in 2001 when the Taliban were ousted from power, he said.

In both countries, Afghanistan and Pakistan, we've made some progress but we're starting to worry about back-tracking on that progress given the high rates of insecurity and the ongoing conflict, Toole said.

The most dramatic indication of back-tracking is the deliberate attacks against girls' schools, he added.

Separately, UNICEF director Ann Veneman spoke to reporters in New York on Thursday about the Convention on the Rights of the Child, a pact aimed at protecting children worldwide that was adopted by the U.N. General Assembly 20 years ago.

Veneman said it was frustrating that Washington has not ratified the pact, noting that the United States and Somalia were the only two states in the world that remain outside it.

The spokesman for the U.S. mission to the United Nations, Mark Kornblau, said that the administration of President Barack Obama was committed to undertaking a thorough and thoughtful review of the Convention on the Rights of the Child.
(Additional reporting by Louis Charbonneau in New York; editing by Philip Barbara)