North Korea offered to suspend nuclear tests on Saturady if the United States cancels its annual military drills conducted jointly with South Korea. Washington quickly rejected the proposal, calling it an "implicit threat."

The proposal was sent to U.S. officials through a "relevant channel" on Friday, according to the North's official KCNA news agency, The Associated Pres reported.

"The message proposed (that) the U.S. contribute to easing tension on the Korean peninsula by temporarily suspending joint military exercises in South Korea and its vicinity this year," said KCNA. "(The message) said that in this case the DPRK is ready to take such a responsive step as temporarily suspending the nuclear test over which the U.S. is concerned."

State Department spokeswoman Jen Psaki said the offer was an "implicit threat" in which Pyongyang was "inappropriately" linking nuclear tests and routine military exercises, which are two separate issues, reported Reuters.

"The DPRK statement that inappropriately links routine US-ROK [South Korea] exercises to the possibility of a nuclear test by North Korea is an implicit threat," Psaki told reporters.

"A new nuclear test would be a clear violation of North Korea's obligations under multiple U.N. Security Council resolutions."

North Korea is currently under U.N. sanctions for setting off atomic devices in its pursuit of a nuclear program.

The U.S. remains open to dialogue, Psaki added, but Pyongyang must "immediately cease all threats, reduce tensions, and take the necessary steps toward denuclearization needed to resume credible negotiations."

A series of joint military drills have been conducted for 40 years between the U.S. and the South, who each insist the drills are defensive in nature, while the North often condemns them as provocative practice for an imminent invasion.

North Korea has conducted three known nuclear tests, the first two in 2006 and 2009, and the latest in February 2013. The country threatened to hold a fourth following a United Nations resolution that condemned its human rights records, reported The Guardian.