The US has rejected North Korea's proposal to sign a peace treaty and stop its annual military drills with South Korea in exchange for Pyongyang halting its nuclear tests.

The statement published by North Korean state news agency on Friday resonated with the country's earlier offers, AP reported.

"Still valid are all proposals for preserving peace and stability on the peninsula and in Northeast Asia including the ones for ceasing our nuclear test and the conclusion of a peace treaty in return for U.S. halt to joint military exercises," the official KCNA news agency quoted a foreign ministry spokesman as saying.

However, the US, which has always maintained that the hermit kingdom should abandon all its nuclear activities, has rejected the latest offer as well, said reports.

US State Department spokesman John Kirby said the country had alliance commitments to Seoul and would continue the military exercises, reported Reuters.

"We are going to continue to make sure the alliance is ready in all respects to act in defense of the South Korean people and the security of the peninsula," Kirby said.

The tensions between Pyongyang and Washington escalated after North Korea claimed to have tested a hydrogen bomb earlier this month.

South Korea recently launched broadcast campaigns against the North by installing electronic bulletin boards along the border, criticising Kim Jong-un's rule. Following this, Pyongyang joined the psychological warfare by flying propaganda leaflets across the border, reported AP.