China rejects North Korea-Iran 'middleman' claims
China has dismissed suggestions it has been a transit point for illegal shipments of ballistic missile material between North Korea and Iran.
UN sanctions were imposed on Pyongyang in 2006 after its first nuclear test, and Beijing says it is conscientious in enforcing Security Council resolutions.
A leaked UN report said technology was being transported by air via a third country, named by diplomats as China.
China responded saying the report lacked credibility.
The report, obtained by Reuters at the weekend, was written by a UN panel of experts monitoring Pyongyang's compliance with the sanctions.
"It does not represent the Security Council's position. Nor does it represent the position of the relevant sanctions committee of the Security County," Foreign Ministry spokeswoman Jiang Yu told the Associated Press in a faxed statement.
"What I can tell you is that China is earnest and responsible in implementing Security Council resolutions," she said.
In a statement to Reuters news agency, Beijing denied it was involved, reiterating that it was conscientious in enforcing the UN resolutions.
The leaked report said North Korea has continued to defy bans imposed by the UN on imports and exports of nuclear-related items, conventional arms and luxury goods.
It says North Korea exploited loopholes and other vulnerabilities in shipping and transportation practices, exchanging ballistic missile technology with Iran on board regular scheduled flights operated by the national carriers Air Koryo and Iran Air.
Cargo flights were used for some transfers, the report says, because security was less stringent than on passenger airlines.
The UN sanctions ban all trade in nuclear and missile technology with North Korea.
The UN has also imposed an arms embargo and subjected some North Korean individuals to travel bans and assets freezes.
North Korea has twice tested nuclear devices - in 2006 and 2009 - and said in September last year that it had entered the final phase of uranium enrichment.
The country is believed to have enough plutonium to make about six bombs, but is not thought to have developed a ballistic missile capable of carrying a nuclear warhead.
The report said North Korea's uranium enrichment programme was "primarily for military purposes" and so Pyongyang should be "compelled to abandon" it and have it placed under international monitoring.
It also raised concerns about safety at the nuclear complex at Yongbyon, warning of an "environmental disaster" if it were to be decommissioned or dismantled without care.