U.S. Secretary of State John Kerry says he's hopeful that the successful conclusion of a nuclear deal with Iran will send a positive message to North Korea to restart negotiations on its own atomic program.

Speaking in Beijing on Saturday, Kerry said he believed an Iran agreement could have "a positive influence" on North Korea, because it would show that giving up nuclear weapons improves domestic economies and ends isolation. He stressed, though, there was no way to tell if North Korea's reclusive leadership would be able to "internalize" such a message.

International negotiators are rushing to finalize a nuclear deal with Iran by the end of June. Nuclear talks with North Korea have been stalled for three years as the North has continued atomic tests and other belligerent behavior.