BEIJING (Reuters) - China's foreign ministry announced countermeasures on Wednesday against nine U.S. military-linked firms over U.S. weapons sales to Taiwan.

The countermeasures taken against firms, including Sierra Nevada Corporation and Stick Rudder Enterprises LLC, became effective on Wednesday, including freezing these firms' property within China, according to a ministry statement.

Organisations and individuals within China are prohibited from engaging in transactions with these firms, the statement said.

(Reporting by Beijing newsroom; Editing by Muralikumar Anantharaman)