China's Communist Party newspaper, the People's Daily, has criticized the United States for demanding that Beijing put more pressure on North Korea to rein in its weapons programs.
It said Beijing "will never accept the 'responsibility' imposed by the U.S."
China accounts for about 90 percent of North Korea's trade.
The newspaper also said sanctions should not interfere with legitimate trade between North Korea and the outside world, or harm everyday people. Sanctions are not "a tool for stifling the regime," it said.
Later, Chinese foreign ministry spokesman Lu Kang told reporters that "some related parties" — a reference to the U.S. and North Korea — "keep sending threatening messages both in words and deeds that include warnings of military action."
"These kinds of actions don't help solve the problem but further complicate the situation," he said.
North Korea launched a missile over Japan on Friday as it protested against tough new U.N. sanctions over its sixth nuclear test on Sept. 3.