The head of the UN nuclear watchdog has echoed President George W Bush's call for better international co-operation to halt the spread of nuclear weapons.
After withdrawing from the NPT, North Korea admitted developing nuclear weapons
Mohammed ElBaradei said quick action was needed to stop terrorists getting hold of nuclear weapons.
Mr Bush's call follows the nuclear smuggling scandal involving a top Pakistani scientist, who sold nuclear secrets to Iran, Libya and North Korea.
China and Japan, as well Pakistan and India have lent their support.
Meanwhile, a Western diplomat in Vienna, where the UN's nuclear watchdog is based, says that inspectors have discovered a new kind of centrifuge in Iran.
Centrifuges are used to produce enriched uranium - a key component of nuclear bombs.
Iran said last November that it had fully disclosed its nuclear programme.
Mr Bush said international treaties intended to regulate the development of nuclear power needed to be strengthened to stop countries producing material which could be used for weapons, such as Iran and North Korea.
He called on the 40 countries of the Nuclear Suppliers Group, which sell nuclear technology, to refuse to sell equipment to any country not already equipped to make nuclear fuel.
Mr Bush also urged law enforcement agencies - including Interpol - to join the battle to prevent the illegal movement of nuclear technology and materials.
The BBC's Rob Watson, in Washington, says the timing of Mr Bush's speech was decidedly political, coming from a president seeking to regain the political initiative in the vital area of national security.
But our correspondent adds that it was nevertheless radical stuff from Mr Bush, who proposed nothing less than the unpicking of the 30-year-old bargain between the nuclear haves and have-nots.
In an editorial in the New York Times newspaper, Mr ElBaradei said: "If the world does not change course, we risk self-destruction."
The head of the International Atomic Energy Agency (IAEA) said there was a "sophisticated worldwide network that can deliver systems for producing material usable in weapons".
Mr ElBaradei proposed:
He also said nuclear powers such as the US, along with Britain, France, Russia and China, should themselves "move towards disarmament".
- A universal control system for the export of nuclear material and technology
- Making snap inspections compulsory for all Nuclear Non-proliferation Treaty (NPT) members
- Not allowing countries to withdraw from the NPT - something North Korea has done recently.
China declared its support for steps to stop illicit trafficking of nuclear material in what correspondents describe as an uncharacteristically prompt response to a US initiative.
"China resolutely opposes the proliferation of WMD as well as its vehicles of transportation. China consistently advocates strengthening international co-operation in the field of non-proliferation," said foreign ministry spokesman Zhang Qiyue.
China's neighbour Japan also echoed the sentiment.
Pakistani nuclear scientist Abdul Qadeer Khan traded nuclear information
"Our country has a great interest in the non-proliferation of weapons of mass destruction from the viewpoint of security," Chief Cabinet Secretary Yasuo Fukuda told reporters.
South Asian nuclear rivals India and Pakistan also joined the chorus of support - with India hinting at the scandal involving the "father of Pakistan's nuclear bomb" Ahmed Qadeer Khan, who has admitted leaking nuclear secrets to Iran, North Korea and Libya.
"Recent examples have showed that non-proliferation obligations have not always been treated with adequate seriousness," an Indian foreign ministry statement said.
Pakistan's Foreign Minister Khurshid Mahmud Kasuri underlined state-to-state co-operation as the best way to deal with "non-state actors" like Dr Khan, who has admitted acting alone, and not telling the government.