The peoples of the world are looking to their leaders to turn past commitments into concrete action

Kofi Annan

The UN hopes that many countries will also commit to initiatives boosting education, health democracy and human rights.

However, much attention is expected to focus on the sidelines of the conference, including US President Bill Clinton's continuing attempts to restart the faltering Middle East peace process.

Mr Annan is also expected to take part in a debate on the need for greater dialogue between civilisations which is to be opened by the Iranian President Mohammad Khatami.

Protests expected

BBC United Nations correspondent Mark Devenport says security is extremely tight for the summit, during which over 90 rallies and demonstrations are expected to take place.

One of the biggest is expected to take place when protesters opposed to the government in Iran gather outside the UN during an address by President Khatami.

Thousands of police officers are on duty, and a number of streets have been closed.

Trucks filled with sand have also been parked at nearby junctions to prevent possible car bomb attacks.