China has strengthened inspections of North Korean cargo transiting through its three northeastern border provinces, while some North Korean restaurants in China have closed their doors, a government source said Wednesday.

The developments follow the U.N. Security Council adopting a fresh resolution of sanctions earlier this month to punish the communist state for its fourth nuclear test on Jan. 6 and long-range rocket test on Feb. 7.

"The circumstances are that Beijing has increased the number of customs officials to conduct near-complete inspections of all cargo going to and from the North," the source said on the condition of anonymity.

"This situation has in fact been observed."

The fresh UNSC resolution calls for mandatory inspections of all cargo leaving and entering the reclusive state among other sanctions. The resolution aims to cut Pyongyang's access to hard currency that can be funneled to its nuclear and missile programs.

The source also pointed out that Beijing has apparently forwarded a directive to local authorities to have them enforce a sanction under the UNSC resolution that bans the entry of 31 ships belonging to the North's blacklisted Ocean Maritime Management company.

Concerning the UNSC sanction targeting the North's financial institutions in foreign countries, the source said that their activities in China had already been suspended since Pyongyang's third nuclear test in February 2013.

Following the fourth nuclear test, which Pyongyang argues was of a hydrogen bomb, some North Korean restaurants in China closed their doors due to the Chinese population's apparent reluctance to use them, coupled with the country's sluggish economic conditions, the source added.

The source said it would take some time to feel the full impact of the UNSC sanctions. "After at least two to three months, the visible result or outcome of the sanctions may emerge," he said. (Yonhap)