US and Iranian Leaders Head for Showdown at Un General Assembly

George Bush and Mahmoud Ahmadinejad will vie for international support with competing speeches to the United Nations tomorrow, in a clash that is likely to be the most dramatic moment in a highly-charged week at the UN.

Their addresses to the UN general assembly will be watched closely for any sign of compromise in the diplomatic struggle over Iran's nuclear program and a simmering "proxy war" for control of Iraq, which have raised fears of a direct conflict.

Mr Ahmadinejad faces widespread protests at New York's Columbia University, where he is due to present a preview of his position today at a foreign policy forum. The university authorities have refused to cancel the event despite angry protests over the Iranian leader's views on the Holocaust and Israel. The demonstrations threaten to bring the city's Upper West Side to a halt.

Before leaving for New York yesterday, Mr Ahmadinejad said Americans were keen to hear his views. "The United States is a big and important country with a population of 300 million. Due to certain issues, the American people in the past years have been denied correct and clear information about global developments and are eager to hear different opinions," he was quoted as saying by IRNA.

More than 70 world leaders will meet today to discuss climate change in an attempt to build momentum for a replacement agreement to the Kyoto accord.

However, the meeting will not include George Bush, Gordon Brown or several other leaders of the big world economies and it is only likely to conclude with a vague communiqué. Its significance will be the pressure it imparts on the US to stay within the UN framework in tackling global warming. The US will be hosting its own meeting of leading economic powers to discuss the same issue in Washington at the end of the week, where Mr Bush will be pushing for a much looser agreement on limiting greenhouse emissions than the deal being pursued by Europe. His plan would allow countries to observe their own targets.

On Saturday, the UN secretary general, Ban Ki-Moon, agreed to increase the UN's role in Iraq with the expansion of its Baghdad office, the reopening of an office in Basra, and the opening of an office in Irbil, in Kurdistan.

Yesterday, it was Afghanistan's turn, as Hamid Karzai met UN member states to appeal for more support for his embattled government in the face of a resurgent Taliban in the south.

At the end of the week, officials from Serbia and Kosovo will hold talks at the fringes of the general assembly meeting. It will be the highest-level encounter between the two sides since the 1999 war, and the first direct meeting in this year's negotiations over Kosovo's future status.

Kosovo is threatening to secede if its independence is not agreed by December 10, the UN deadline for the current round of talks to end. Russia supports Serbia's effort to block independence and argues that December 10 should not mark the end of diplomacy.

A senior Russian diplomat said Moscow still believed a compromise could be reached. "Both parties are only at the beginning of an interesting process of bridging their first asking positions," a senior Russian diplomat said.

"There are a lot of interesting precedents, like the coexistence of the two Germanies, for example, or Palestine and Israel."

However, most attention is likely to be focused this week on Iran and its nuclear program, because of the potentially devastating implications of another war in the Gulf.

At a meeting of diplomats in Washington on Friday, there was agreement in principle that there should a third round of sanctions against Iran for failing to heed security council demands to stop enriching uranium. However Russia, with Chinese support, argues that there is no hurry to impose the new sanctions while Iran is cooperating with the International Atomic Energy Authority over unresolved questions about its program. Russia wants no action before a scheduled visit by President Putin to Tehran next month.

In the absence of a security council consensus, the US, Britain and France will investigate other ways of raising the pressure on Tehran, imposing their own unilateral and joint sanctions, and increasing the scope of the existing embargo.

The week ahead

Today
Mahmoud Ahmadinejad, the president of Iran attends a forum at Columbia University in New York, amid heated controversy over his appearance

The biggest-ever meeting of world leaders on climate change is held, intended to be a statement of collective determination to deal with the problem under the auspices of the UN

Tuesday
George Bush and Mr Ahmadinejad address the UN general assembly.

Friday
David Miliband, the foreign secretary, addresses the UN

First direct meeting for many years between senior Serbian and Kosovan officials over the Kosovo's future

Meeting between the UK, France, Germany, US, Russia and China on Iran's nuclear program.