The US State Department on Thursday imposed sanctions on a Chinese research institute and several companies it said have been involved in supplying Pakistan's ballistic missile programme.

Washington similarly targeted three China-based companies with sanctions in October 2023 for supplying missile-applicable items to Pakistan.

Department spokesperson Matthew Miller said in a statement that the Beijing Research Institute of Automation for Machine Building Industry had worked with Pakistan to procure equipment for testing rocket motors for the Shaheen-3 and Ababeel systems and potentially for larger systems.

The sanctions also targeted China-based firms Hubei Huachangda Intelligent Equipment Co, Universal Enterprise, and Xi'an Longde Technology Development Co, alongside Pakistan-based Innovative Equipment and a Chinese national, for knowingly transferring equipment under missile technology restrictions, Miller said.

"As today’s actions demonstrate, the United States will continue to act against proliferation and associated procurement activities of concern, wherever they occur," Miller said.

Liu Pengyu, spokesperson for China's embassy in Washington, said: "China firmly opposes unilateral sanctions and long-arm jurisdiction that have no basis in international law or authorization of the UN Security Council."

China will "firmly protect" Chinese companies' and individuals' rights and interests, Liu said.

Pakistan's embassy did not immediately respond to a request for comment.

Last year also, the United States had imposed sanctions on three China-based companies that it said worked to supply missile‐applicable items to Pakistan’s ballistic missile program. A State Department statement identified the firms as General Technology Limited, Beijing Luo Luo Technology Development Co Ltd, and Changzhou Utek Composite Company Ltd.

It said General Technology had worked to supply brazing materials used to join components in ballistic missile rocket engines and in the production of combustion chambers; Beijing Luo Luo had worked to supply mandrels and other machinery, which can be used in the production of solid-propellant rocket motors, the US said.

The third firm, Changzhou Utek Composite, had worked since 2019 to supply D-glass fiber, quartz fabric, and high silica cloth, all of which have applications in missile systems, the statement had said.

"Today's actions demonstrate that the United States will continue to act against proliferation of weapons of mass destruction, their means of delivery, and associated procurement activities of concern, wherever they occur," the statement said back then.