BEIJING (AFP) - Ten days after North Korea staked its claim as a nuclear power with its first atomic test, Chinese President Hu Jintao dispatched a senior envoy to Pyongyang to defuse the escalating global crisis.

North Korea had defied its closest ally, most important source of aid and biggest trading partner by conducting the nuclear explosion just 200 kilometres (120 miles) from the two nations' border, and Hu clearly was not amused.

China rarely makes public its sensitive dealings with other nations, but on this occasion it looked keen to show it was making big efforts to rein in its communist neighbor.

It announced that Tang Jiaxuan, a former foreign minister, had met Kim Jong-Il to make the first confirmed direct contact between a foreign official and the communist leader since North Korea conducted its October 9 atomic test.

"This is a very significant visit against the backdrop of major changes in the situation on the Korean peninsula," foreign ministry spokesman Liu Jianchao said at the time, adding Tang had delivered an "important" message.

The visit was part of a concerted campaign by China to rein in North Korea, the benefits of which could be seen in Tuesday's six-nation deal that saw Pyongyang agree to suspend its nuclear facilities, Chinese and Western analysts said.

"I think Tang Jiaxuan told North Korea not to go too far, that the international community was very concerned about the nuclear test and the situation was very serious," Huang Dahui, a director of research at the People's University Centre on Eastern Asia Studies in Beijing, told AFP.

John Feffer, a U.S.-based Korea expert and global affairs director at the International Relations Centre, said Tang had also most likely warned Kim about the many drawbacks in conducting a second nuclear test.

Feffer said other pressure China placed on North Korea in a bid to encourage it to wind back its nuclear program was a discreet reduction in oil supplies, some food aid and currency transactions.

However, he said China was always careful not to apply so much pressure that Kim's rule may have been jeopardized as, for many reasons, Beijing does not want regime-change in North Korea.

And while North Korea does listen to China, ultimately it acts for its own reasons and not at the behest of its "big brother", according to Feffer.

"North Korea will certainly do things that China asks it to do, if it fits in with its own strategies and goal," Feffer said.

Scott Bruce, a U.S.-based operations director with the Nautilus Institute public policy think-tank, agreed and said a key part of China's campaign was to show North Korea that winding back its nuclear ambitions was in its own interests.

"China was always very clear in showing North Korea what they had to gain," Bruce said.

These benefits partly materialized in Tuesday's deal, which saw North Korea promised 50,000 tons of fuel oil for closing its key nuclear facilities in 60 days and another 950,000 tons for permanently disabling them.

For North Korea that part of the deal was worth around 300 million dollars, according to Victor Shum, a Singapore-based oil analyst.

The United States also committed to holding direct talks on establishing diplomatic ties with North Korea, begin looking at removing it from its list of terrorist nations and quickly end a long-running dispute over financial sanctions.

Chief U.S. negotiator Christopher Hill praised China on Tuesday for helping to broker the deal.

"We are so appreciative of the efforts of the Chinese," Hill said. "The Chinese worked very hard to keep everybody on task and to really close the deal."