We aren't helping any South Asian countries develop nuclear weapons or missiles that can carry nuclear weapons

Sun Yuxi, Chinese Foreign Ministry

"I want to state clearly that there is no such thing as Chinese sales of missile technology to Pakistan," Foreign Ministry spokesman Sun Yuxi told a news conference in Beijing.

But he added that China would this week resume weapons proliferation talks with the US that were suspended following the Nato bombing of its Belgrade embassy last year.

Pakistan has also denied that it has received Chinese help

The announcement follows reports in the New York Times on Sunday that US intelligence had observed China stepping up the shipment of weapons-grade steel, guidance systems and technical expertise to Pakistan.

The report also said that Chinese personnel had been seen at missile development sites inside Pakistan within the last eight months.

On Monday, the Pakistani Government also dismissed the report's allegations saying it had no missile co-operation with China "at the present moment".

Foreign Minister Abdul Sattar said that his country's missile programme was so far advanced "that we can continue the process of research ourselves".

Arms race

Two years ago Pakistan conducted a series of nuclear test explosions in response to similar detonations carried out by India.

The nuclear shadow is hanging over the subcontinent

The nuclear tests dramatically raised tensions on the subcontinent and sparked warnings that the two rival states could fall into a dangerous arms race.

The allegations of Chinese nuclear assistance to Pakistan come at a time when Washington is trying to patch up its battered relations with Beijing.

Last week, US Secretary of State Madeleine Albright held talks in the Chinese capital designed to restore constructive dialogue undermined by the Belgrade embassy bombing.

And on Thursday a US delegation headed by the senior State Department disarmament official John Holum is due to arrive in Beijing.

Missile exports

In Washington officials have taken care not to comment on the New York Times allegations, although they have pointed to China's improved record in other areas of arms exports.

Reports say Chinese personnel were seen at Pakistani missile sites

The controls on the export of missile technology remains an area of concern for Washington.

It has been trying to get China to join the Missile Technology Control Regime, which is meant to limit the spread of rockets with a range of more than 300 kilometres.

China, according to the Americans, has said only that it would abide by the regime's provisions.

However, arms control experts increasingly believe there is a clandestine network of countries helping each other develop missiles in the face of international efforts to stop them.

Suspect states

China Pakistan North Korea Iran Syria Libya

As well as China and Pakistan, they include North Korea, Iran, Syria, and Libya.

Analysts point to the remarkable similarities between the latest medium-range ballistic missiles tested by North Korea, Pakistan, and Iran.

It is also reported that engineers from each of these countries have attended the others' tests.

The last occasion when China is known to have sent missile technology to Pakistan was in 1993 when it sent several complete missiles, apparently in retaliation for the US Government's sale of F-16 fighter planes to Taiwan.