US looks to China, Japan to act on N Korea ban

The UN Security Council unanimously approved on Saturday a US-drafted package of financial and weapons sanctions against North Korea, which -- defying international pressure -- said last week that it had conducted a nuclear test.

"A return to six-party talks kind of doesn't do it," US Ambassador to Japan Thomas Schieffer told a small group of journalists. "You have to come to the six-party talks and agree on how you are going to implement the September 19 agreement."

"If that implementation could then be verified by the international community, I think you would see walking back from the sanctions regime."

Meanwhile, China has been building a massive barbed wire and concrete fence along parts of its border with North Korea in the most visible sign of Beijing's strained ties with its once-cozy communist neighbour.

Scores of soldiers have descended on farmland near the border-marking Yalu River to erect concrete barriers 8 to 15 feet tall and string barbed wire between them, farmers and visitors to the area said.

Last week, they reached Hushan, a collection of villages 12 miles inland from the border port of Dandong.

"About 100 People's Liberation Army soldiers in camouflage started building the fence four days ago and finished it yesterday," said a farmer, who only gave his surname, Ai. "I assume it was built to prevent smuggling and illegal crossing."

Though the fence-building appears to have picked up in the days following North Korea's claimed nuclear test last week, experts said the project was approved in 2003. Experts and a local Hushan official, who requested anonymity because of the sensitivity of the project, said the military was in charge of the building.