Pyongyang's announcement of a plan to fire four missiles near the US territory of Guam dramatically escalates tensions on the Korean Peninsula, but could also be a ploy, Chinese experts said.

It is possible that Pyongyang issued the threat as a bargaining chip to make a deal with Washington, they said.

The Democratic People's Republic of Korea military has said its plan to fire four intermediate missiles to land 30 to 40 km from Guam will be ready by mid-August and its implementation will depend on a decision by DPRK leader Kim Jong-un, the Korean Central News Agency said on Thursday.

The plan came after the DPRK dismissed as a "load of nonsense" warnings by US President Donald Trump that it would face "fire and fury" if it threatened the United States.

Guam became a US territory in 1898, and the US maintains a naval and air force base there.

"Pyongyang's move will equal suicide if implemented, as Washington will retaliate," said Zhang Liangui, an expert in Korean studies at the Party School of the Central Committee of the Communist Party of China.

Since 2005, the DPRK has carried out five nuclear tests and numerous missile tests, including two ballistic missile tests in July. Escalating tensions on the peninsula erupted into an exchange of fierce rhetoric with the US this week.

China described the situation as "complex and sensitive" and urged calm and a return to talks.

"China calls on all sides to uphold the main direction of a political resolution to the Korean Peninsula nuclear issue and avoid any words or actions that may intensify the problem and escalate the situation," the Foreign Ministry said in a statement sent to Reuters.

"It is also possible that Pyongyang only wants Washington to acknowledge that it is a nuclear power by announcing the plan instead of really implementing it. After all, it likes to be unpredictable," Zhang said.

Wang Junsheng, a researcher on Asia-Pacific studies at the Chinese Academy of Social Sciences, said, Pyongyang is more likely bluffing because its ability to strike near Guam at the technical level remains uncertain.

Zhou Jin contributed to this story.

mojingxi@chinadaily.com.cn