Beijing  - Deadlocked negotiations on dismantling North Korea's nuclear weapons programme are likely to break up Thursday as Pyongyang rejected a compromise proposal on procedures to verify its disablement.

In the latest round of the six-party talks, delegates from the United States, China, Japan, Russia and South Korea struggled with North Korea's continued refusal to allow nuclear inspectors to take soil and waste samples from its nuclear facility in Yongbyon, a means to verify how much plutonium for nuclear weapons the country produced.

North Korea on Wednesday rejected draft by meeting host China, which included a clause on environmental sampling.

""There are several core contents in a (planned) verification protocol, especially scientific procedures including sampling. North Korea said it can't accept that. It gave fundamental and comprehensive reasons," South Korean chief negotiator Kim Sook was quoted as saying after Wednesday's evening session by South Korea's official Yonhap news agency.

"We have not achieved our goal," US chief negotiator Christopher Hill said. "It's not trending in the right direction."

As the Beijing talks entered its fourth day, delegates indicated they expected it to break up. Chinese Foreign Minister Yang Jiechi called a meeting to discuss the deadlock.

Under a 2007 accord, North Korea vowed to give up its nuclear weapons programme, in exchange of substantial economic and energy aid as well as improved diplomatic ties with the United States. (dpa)