The U.S. reportedly believes China intervened with North Korea to calm growing tensions on the Korean Peninsula.

The Wall Street Journal (WSJ) quoted a senior Obama administration official as saying Thursday that Beijing played a key role in convincing North Korea not to retaliate to a South Korean artillery exercise that was held on Monday.

According to the report, the official portrayed China as increasingly frustrated with the North's actions, which also included its disclosure in November of a new uranium-enrichment facility, and said China's "view has been changed about the need to act" by the "sheer outrageousness" of the North's moves.

Earlier on December fifth, China sent State Councilor Dai Bingguo to Pyongyang shortly after Chinese President Hu Jintao held talks with U.S. President Barack Obama over the phone.

Attention is on whether China will seek changes to its policies on Pyongyang, as the U.S. has urged China to play a more active role with regard to the North and as Hu is slated to visit Washington next month.