China called for restraint on Tuesday over signs that North Korea may conduct its fifth nuclear test ahead of a rare party congress early next month.

The possibility of North Korea carrying out another nuclear test has grown after the failed test of an intermediate-range ballistic missile last week, as Pyongyang is trying to bolster internal solidarity ahead of the May party congress, South Korean officials said.

The U.N. Security Council adopted tougher sanctions against North Korea early last month over the North's fourth nuclear test in January and launch of a long-range rocket in February.

"We hope that all parties can exercise restraint, be prudent with words and deeds, and refrain from taking any actions that may escalate the current tension," said China's foreign ministry spokeswoman Hua Chunying when asked about signs of North Korea preparing another nuclear test.

Hua also repeated that the U.N. sanctions against North Korea must be sincerely implemented.

"We believe that the U.N. Security Council resolutions should be fully and earnestly implemented especially under the current circumstances," Hua said. (Yonhap)