WASHINGTON - Diplomatic negotiation is the only way out for the Korean Peninsula nuclear issue, Chinese Ambassador to the United States Cui Tiankai said here this week.

Speaking at the 7th US-China Civil Strategic Dialogue on Monday, Cui said the Korean Peninsula nuclear issue is in essence an issue of security and the key to escape the "security dilemma" is to start with addressing legitimate security concerns of all sides.

"Sanctions are necessary, but sanctions only cannot solve the problem. The impact of sanctions would be maximized only when it is combined with more robust efforts for the resumption of negotiations," said Cui.

US Secretary of State Rex Tillerson had in the past months repeatedly claimed that "the policy of strategic patience has ended."

"We hope it will lead to proactive actions on the diplomatic front, not strategic impatience instead," said Cui.

"There are now calls for military actions. China's position on this is firm and clear. We would never allow war or chaos breaking out on the Korean peninsula. The cost would be too high for anyone, including the US," he added.

Stressing that China is committed to a denuclearized Korean Peninsula and no one should deny China's persistent efforts toward that goal, Cui dismissed some media reports as "distorted" which indicated that trade between China and the Democratic People's Republic of Korea (DPRK) increased in the first quarter of this year.

"In fact, trade between China and the DPRK has been declining in 2015 and 2016. In February this year, China suspended coal import from the DPRK. As a result import from DPRK has dropped 41 percent in April and 32 percent in May year-on-year," said Cui, adding that UN Security Council sanctions against the DPRK do not constitute an embargo.