Three large Chinese banks could lose their access to the U.S. financial system after a judge found them in contempt for refusing to comply with subpoenas in a probe into violation of North Korean sanctions, The Washington Post reported on Monday.

The three banks are not identified by the judge, but details in the court ruling align with a 2017 civil forfeiture action against Bank of Communications, China Merchants Bank and Shanghai Pudong Development Bank, according to the report.

The U.S. Department of Justice back then accused the banks of working with a Hong Kong company, which allegedly laundered over $100 million (10.7 billion yen) for North Korea's sanctioned Foreign Trade Bank, according to the paper.

A spokesman at China Merchants Bank said he was aware of the report but could not immediately comment. Shanghai Pudong Development Bank and Bank of Communications could not be reached immediately for comment.

The report comes as the United States and China have been engaged in a trade dispute for months on issues such as tariffs, subsidies, technology, intellectual property and cyber security, among others.

The U.S. government has put some Chinese companies, including telecommunications equipment maker Huawei Technologies Co., Ltd., on a trade blacklist while China is also drawing up its own "Unreliable Entities List" of foreign firms, groups and individuals.

U.S. President Donald Trump and Chinese President Xi Jinping will meet this week at the Group of 20 summit in Japan hoping to calm their 11-month trade war.