China is promising to take action against U.S.-sanctioned companies if it sees "solid evidence" they illegally helped North Korea, while cautioning against the imposition of outside laws on Chinese citizens.

Foreign Ministry spokeswoman Hua Chunying told reporters Thursday she had no information on entities targeted by new U.S. sanctions, but that those violating U.N. Security Council resolutions or Chinese law will be dealt with strictly.

The Trump administration announced sanctions Wednesday on North Korean business networks in China and Russia as it pushed to cut off revenues for the increasingly isolated nation's nuclear program.

The U.S. has tightened sanctions significantly in the past year as tensions rise with North Korea. While Beijing and Moscow have supported U.N. restrictions, they bristle at Washington imposing unilateral sanctions to put pressure on Pyongyang.