The UN Security Council has unanimously backed sanctions against North Korea in the wake of its claimed nuclear test.
The BBC News website looks at what sanctions are now in place, and the stance of some of the key countries involved.
Despite easing 50-year-old sanctions against North Korea in 2000, the US has had limited trading relations with Pyongyang amid suspicion over its nuclear plans.
Since 2002, when relations began to seriously deteriorate, the US has been calling for a much tougher stance by the international community against North Korea.
In 2003, it launched the Proliferation Security Initiative (PSI) with the aim of intercepting weapons from North Korea, Iran and other countries of concern.
Participating countries were called on to search aircraft and ships suspected of carrying weapons-related material.
In September 2005, Washington imposed financial sanctions on North Korea, accusing it of involvement in the laundering of drug money and counterfeit currency.
It froze the assets of eight firms it believed to be linked to the proliferation of weapons of mass destruction, and acted against a bank in Macau accused of helping launder money and of having links with the North Korean leadership.
Following North Korea's test launching of seven missiles in July 2006, the UN Security Council condemned North Korea and called on all members to stop missiles and missile-related technology being transferred to North Korea.
The US took action against 12 companies and one individual under these sanctions.
Following North Korea's claimed nuclear test, the US pushed through a UN resolution that calls for a series of sanctions against Pyongyang.
These include a ban on the imports and exports of military hardware, nuclear and missile-related items and luxury goods, as well as the travel of anyone involved in North Korea's missile and nuclear programmes.
The resolution also allows for the inspection of North Korean cargo, but, in a bid to ease Chinese and Russian concerns, stresses the need for a new resolution if further action is sought.
Two days after the nuclear test, Japan announced new unilateral sanctions banning all North Korean imports and prohibiting North Korean ships from entering Japanese ports.
North Korean nationals, with a few exceptions, were also barred entry into Japan.
The import ban will hit vital North Korean money-making exports such as mushrooms and clams, as well as coal. Cars, trucks and buses are Japan's main exports to North Korea.
The sanctions came on top of those already imposed after North Korea's missile tests in July 2006.
Japan was instrumental in pushing through that UN resolution, which called on all member states to prevent imports from or exports to North Korea of materials that could be used in weapons of mass destruction.
Tokyo also suspended food aid to North Korea, introduced limited financial sanctions and banned the main North Korean ferry service between the two countries.
South Korea has been actively trying to engage the North under its so-called "Sunshine Policy" and has stepped up economic, political and humanitarian contacts.
But the policy has drawn criticism from its main ally, the US, and a growing number of people at home who demand a stronger line towards Pyongyang.
After July's missile tests, South Korea cut off regular humanitarian aid, including rice and fertiliser to the North.
But it has been reluctant to support stronger measures for fear of raising tensions with its neighbour. It also fears political or economic collapse in North Korea since this could lead to millions of refugees crossing its border.
For these and other reasons, South Korea had been reluctant to join the US-led Proliferation Security Initiative.
However, following North Korea's claimed nuclear test, Vice-Foreign Minister Yoo Myeong-hwan said the South planned to join "on a partial and case-by-case basis."
China is Pyongyang's largest trading partner and closest ally, and played a key role in the now stalled negotiations over North Korea's nuclear programme.
Beijing has flatly condemned North Korea over its nuclear test, but like South Korea it wants to see a stable neighbour and has resisted tough measures called for by the US.
It voted for the UN resolution in July banning missile-related imports, but only after any mention of Chapter Seven, which would have allowed for military action, was removed.
China again called for restraint following North Korea's claimed nuclear test. It agreed to the resolution after a new clause was inserted which made clear that any further action - including a military response - would need to be approved by a fresh resolution.
While Beijing supports the sanctions approved in the resolution, it has indicated it still has reservations about carrying out inspections of North Korean ships, especially when they are still at sea, in case it triggers a flare up with the North's navy.
Russia had strong ties with North Korea during the Soviet era and sees the country as a potential transit route for energy pipelines.
Like China - another veto-wielding member of the UN Security Council - Russia has been inclined towards coaxing the North rather than punishing it.
Russia has also condemned North Korea's nuclear test and supported the UN resolution approving sanctions against Pyongyang.
But it has again said military action is not the answer, and wants to see the issue resolved through diplomatic means
Australia, along with Japan, followed the US by announcing financial sanctions against North Korea in September 2006.
The sanctions involved freezing the transfer of money to North Korea by 12 groups and one person suspected of having links to its nuclear or missile programmes, Canberra said.
Following the UN resolution approving sanctions against Pyongyang, Australia said it would be banning North Korea ships from its ports.