China has added three U.S. firms -- Saronic Technologies, Inc., Aerkomm Inc. and Oceaneering International, Inc. -- to its unreliable entity list, the country's commerce ministry announced Thursday.

These companies, in disregard of strong opposition from China, have in recent years engaged in so-called military technology cooperation with Taiwan, seriously undermining China's national sovereignty, security and development interests, a spokesperson for the ministry said in a statement.

China holds the three firms accountable for their unlawful activities, in accordance with relevant laws and regulations, according to the statement.

China always handles issues related to its unreliable entity list prudently, and only targets the very few foreign entities that undermine China's national security, the spokesperson said.

"There is nothing to worry about for honest and law-abiding foreign entities," said the spokesperson.

The Chinese government, as always, welcomes companies from all countries to invest and operate in China, and is committed to providing a stable, fair and predictable business environment for foreign enterprises that operate in accordance with laws and regulations, said the spokesperson.