Senior Chinese and Japanese diplomats discussed ways to resume long-stalled talks aimed at dismantling North Korea's nuclear weapons program, according to China's foreign ministry on Tuesday.

Wu Dawei, China's chief envoy to the six-party talks, held talks with his Japanese counterpart, Junichi Ihara, on Monday in Beijing during which they exchanged views on resumption of the talks with North Korea, the Chinese ministry said in a brief statement.

The meeting between Wu and Ihara came as the U.S. special representative for North Korea policy, Sung Kim, is set to hold three-way talks in Seoul on Tuesday with his South Korean and Japanese counterparts, Hwang Joon-kook and Ihara.

On Thursday, the U.S. envoy will travel to Beijing and hold talks with Wu.

This week's regional diplomacy comes as North Korea claimed it successfully test-launched a ballistic missile from a submarine.

If confirmed, the submarine-based ballistic missile test by North Korea, which has conducted three nuclear tests so far, would pose a major security threat to South Korea and Japan.

The six-party talks, involving South Korea, North Korea, the U.S., China, Japan and Russia, have been dormant since late 2008.

Since then, North Korea has advanced its nuclear capabilities by conducting its second and third nuclear tests in 2009 and 2013.

Some experts now warn that the communist nation's nuclear arsenal could expand to 100 bombs by 2020. (Yonhap)