STOCKHOLM, Oct 5 (Reuters) - Working-level nuclear talks between North Korea and the United States have broken off, North Korea's chief negotiator said on Saturday.

"The negotiations have not fulfilled our expectation and finally broke off," the North's chief nuclear negotiator, Kim Myong Gil, told reporters through an interpreter outside the country's embassy in Stockholm.

The North Korean delegation arrived in Stockholm on Thursday for the working-level denuclearization talks.

North Korea said on Wednesday it had successfully test-fired a new submarine-launched ballistic missile. The launch was the most provocative by North Korea since it resumed dialogue with the United States in 2018. U.N. Security Council resolutions ban Pyongyang from using ballistic missile technology. (Reporting by Johan Ahlander, Philip O'Connor and Simon Johnson; Editing by Hugh Lawson)