Audio Transcript:

Marco Werman: I'm Marco Werman, this is The World. North Korea said it would conduct another nuclear test. The international community warned it not to, but today the North Koreans went and did it anyway. And this was the reaction from passersby in Pyongyang Square when they saw the news of the nuclear tests flash on a giant screen there. And this Pyongyang resident said she was excited about the news.

Pyongyang resident: [speaking Korean]

Werman: The woman said she was proud of North Korea's accomplishment. She added that the test boosts the nation's faith in its ability to fight any enemy. That last statement like the North Korean government's propaganda is aimed squarely at the US. It sends a threatening message to Washington just hours before President Obama's state of the union address tonight. The test also represents a challenge for North Korea's traditional ally next door, China. Tania Branigan is with The Guardian newspaper and is in Beijing. So we heard from a North Korean citizen a moment ago on the street talking about the pride that that new test filled them with and their belief that this proves their nation's military might. I suspect a different sort of reaction in China. What is the China's central government saying about this test?

Tania Branigan: Well, China has made it very clear that it's not happy. It's actually called in the North Korean ambassador and it's also signed up for the UN Security Council's resolution recently, which specifically warned the north of conducting future missile or nuclear tests. And they seem to be taking a much stronger line perhaps on the North this time. Now, they haven't gone quite as far as they did back in 2006 when the first nuclear test took place. Back then they talked about Pyongyang's brazen behavior, and so they were a little outspoken, but there is a feeling here that perhaps their patience is really starting to run out.

Werman: Right, and if that patience does indeed bottom out would China consider cutting ties with North Korea?

Branigan: No, they're not going to be cutting off the North completely. They're long term allies, although there's always been a relationship where there's quite a lot of mutual suspicion going back decades. But China is still the north's main supplier of aid, it's main trade partner and that's really not going to change. Now, there's a feeling certainly in the West that China doesn't do enough on North Korea, that if it chose to it could certainly exert more pressure on it, for example, by cutting off some of the flow of oil or of food into a country which is obviously very poor and really needs those resources. But at the same time from China's point of view it doesn't want to destabilize the North. It really doesn't want to see the regime collapse for a number of reasons. It doesn't want to see refugees trying to flood over the border. It doesn't want to see in the even of unification, US troops arriving right up at its border. I mean I think the key thing really is that the government has thought to try and engage economically with North Korea and to some extent, they've seen that that's really a way of trying to get North Korea back into a negotiating position, improve relations to a point where perhaps there's a little bit more trust. I mean it's also worth saying that it has been quite useful for China in terms of general diplomacy in the region to be able to say well look, we're the people who have influence over North Korea and we're doing our best to reign them in, but some people would argue that China really talks up what it does while not having as much clout as the outside world tends to think.

Werman: Tania Branigan with The Guardian newspaper in Beijing there.