There can be no winners in a war between the U.S. and North Korea over Pyongyang's nuclear weapons and missile programs, Chinese Foreign Minister Wang Yi said, while pledging support for dialogue between the sides.

Wang's comments Friday mark the latest attempt to cool tensions by North Korea's most important ally and key provider of food and fuel aid. Any fighting on the Korean Peninsula is likely to draw in China, which has repeatedly expressed concerns about a wave of refugees and the possible presence of U.S. and South Korean troops on its border.

China also has grown increasingly frustrated with the refusal of Kim Jong Un's regime to heed its admonitions, and in February cut off imports of North Korean coal that provide Pyongyang with a crucial source of foreign currency.

State media reported late Friday that starting Monday, the Chinese flag carrier Air China will cancel flights from Beijing to Pyongyang due to poor ticket sales.

A booking hotline operator reached Saturday said there were no more flights to Pyongyang for the rest of the month. She said that according to a flight schedule, there would be flights in May, June and July, but that tickets were not available for booking or purchase yet.

Air China and North Korea's Air Koryo are the only two airlines serving that route, with the latter operating on Mondays, Wednesdays and Fridays.

"Once a war really happens, the result will be nothing but multiple loss. No one can become a winner," Wang told reporters at a news conference with French Foreign Minister Jean-Marc Ayrault.

"Therefore, we call upon all the parties, no matter verbally or in action, to stop provoking and threatening each other and not to allow the situation to become irretrievable and out of control," Wang said.

He urged all sides to take a flexible approach to resuming dialogue.

"As long as dialogue takes place, it can be official or unofficial, through one channel or dual channels, bilateral or multilateral. China is willing to give support to all of them," Wang said.

Wang last month urged North Korea to suspend its nuclear weapon and missile tests in exchange for South Korea and the U.S. putting their war games on hold, reviving a proposal first raised by Pyongyang. Washington swiftly dismissed the idea, but some observers have said administration officials may be becoming more amenable to renewed dialogue with the North.

Earlier Friday, North Korea's Vice Minister Han Song Ryol told The Associated Press in an exclusive interview that his country will keep building up its nuclear arsenal in "quality and quantity" and said Pyongyang is ready to go to war if that's what President Donald Trump wants.

Chinese experts said they see little immediate possibility of hostilities breaking out, but warned that Beijing will respond harshly to any further North Korean nuclear tests.

Director of Jilin University's Institute of Northeast Asian Studies Guo Rui said that Trump's domestic troubles should prevent him taking such action, while North Korea doesn't appear to be on a war footing. Another nuclear test would invite tougher measures from Beijing, Guo said.

Pang Zhongying of the School of International Studies at Beijing's Renmin University agreed that military action was unlikely, but said another North Korean nuclear test would mark "the crossing of a red line" that China was prepared to respond to.