UPDATE 1-N.Korea says U.S. responsible if diplomacy over Korea peninsula breaks down

(adds background, vice minister's quotes in paragraph 2, 6)

SEOUL, Nov 22 (Reuters) - The United States will be held responsible if the opportunity for diplomacy over the Korean peninsula issue is lost, North Korea's vice foreign minister was quoted as saying by the South's Yonhap news agency on Friday.

The comments by Vice Minister Choe Son Hui, who is a close aide to North Korean leader Kim Jong Un and a one of the North's key nuclear negotiators, were the latest effort by Pyongyang to press Washington for a change in attitude amid stalled nuclear negotiations.

"The United States would have to take full responsibility if the opportunity for diplomacy disappears in Korean peninsula for (the U.S.) not taking corresponding measures," Choe told reporters in Moscow after meeting Russian officials, according to the Yonhap report.

She did not elaborate on the corresponding measures she referred to were.

Choe had said on Wednesday that another summit between North Korean leader Kim Jong Un and U.S. President Donald Trump would be impossible until the U.S. "hostile policy" towards Pyonyang was removed.

North Korea has also called for an end to joint military drills between the United States and South Korea, as well as for the lifting of international sanctions that were imposed for its nuclear and ballistic missile tests, which it halted in late 2017.

Choe said the North had "given time and taken steps to build confidence", but all it had received in return was "a sense of betrayal".

When asked about the U.S. Special Representative for North Korea, Stephen Biegun, designating Choe as his counterpart, she responded by saying "negotiation representatives are nominated by each country". (Reporting by Jack Kim and Joori Roh; Editing by Alex Richardson)