South Korea said Monday that North Korea is believed to be relying on cash delivery or borrowed-name bank accounts in a bid to avert China's possible financial sanctions.

A local media company reported that Chinese banks in areas bordering North Korea have begun to freeze accounts held by North Koreans apparently in response to the North's latest nuclear and missile test.

The Unification Ministry said that it is checking the validity of the report.

"But the North is thought to directly deliver cash or use borrowed-name bank accounts when it comes to its external trade (with China)," said Jeong Joon-hee, a ministry spokesman at the regular press briefing.

China is under pressure to join U.S.-led efforts to slap more stringent sanctions on North Korea. The North carried out its fourth nuclear test last month, followed by its long-range rocket launch earlier this month.

In 2013, the Bank of China closed accounts with North Korea's Foreign Trade Bank, which was accused by the U.S. of helping finance the North's nuclear weapons program.

Washington's unilateral financial sanctions hit Pyongyang hard in 2005.

The U.S. blacklisted the Macau-based Banco Delta Asia bank for alleged counterfeiting and money laundering by North Korea. The move froze about $24 million worth of funds in North Korea's accounts at the BDA. (Yonhap)