The US says it will pursue UN sanctions against Iran more than two weeks after a deadline to halt uranuim enrichment passed. Hopes of continuing talks on Iran's nuclear program in New York are in doubt after the country's top nuclear negotiator failed to

Ali Larijani was due to arrive in the US to attend the UN General Assembly but has failed to arrive on schedule. The EU's head of foreign policy said he still had plans to meet Larijani in New York. US ambassador to the UN, John Bolton, says the threat of UN sanctions remains unless there is a diplomatic breakthrough. Security in New York has been stepped up as delegates from almost 200 countries arrive for the General Assembly.

Among those attending is Iranian president Mahmoud Ahmadinejad. He's travelling from Venezuela where he met with the country's president, Hugo Chavez. Ahmadinejad will address the assembly later on Tuesday, as will President Bush. But the Iranian leader has been denied a one-on-one meeting with Bush who says Iran must first halt its uranium enrichment activities.