Chinese Foreign Minister Li Zhaoxing on Wednesday joined world leaders in signing an international treaty under which defines as a crime the possession of radioactive material with the intention of committing a terrorist act.

The Convention for the Suppression of Acts of Nuclear Terrorism was the 13th anti-terrorism international treaty and the first completed since the Sept. 11 terrorist attacks on the United States.

The accord, adopted by the UN General Assembly in April, will enter into force after 22 states ratify it.

Under the treaty, it is illegal to possess radioactive material or a nuclear device for the purpose of causing death or substantial damage to property or environment. It is also punishable to threaten to use radioactive material or attempt to obtain such lethal material.

After Li signed the treaty at a desk in a makeshift hall on the sidelines of the UN summit, Chinese UN Ambassador Wang Guangya told reporters that China's signing of the treaty indicates the country's determination to combat terrorism and its support for the UN's leading role in the global fight against terrorism.

Other leaders who signed the document Wednesday included Russian President Vladimir Putin, US President George W. Bush, French Prime Minister Dominique de Villepin and Canadian Prime Minister Paul Martin.

Source: Xinhua