The US has imposed sanctions on four companies from China and Russia for supporting Iran’s missile programme that remains a “significant proliferation concern,” Secretary of State Mike Pompeo has said.

The announcement was made on Friday as the US continues to take tough measures against Iran for continuing their activities related to nuclear arms.

“The US has sanctioned four entities in China and Russia for their support of Iran’s missile programme, which remains a significant proliferation concern. We will continue to use all our sanctions tools to prevent Iran from advancing its missile capabilities,” Pompeo said.

The companies are Chengdu Best New Materials Co Ltd and Zibo Elim Trade Co, Ltd. in China and Nilco Group, which is also known as Nil Fam Khazar Company and Santers Holding and Joint Stock Company Elecon in Russia for transferring sensitive technology and items to Iran’s missile programme.

President Donald Trump withdrew the US from the landmark Iran nuclear deal in 2018. After withdrawing from the Iranian nuclear deal, Trump has asked all countries to reduce their purchase of oil from Iran to zero or face secondary sanctions.

Iran insists its nuclear programme is for peaceful purposes. Pompeo said all countries need to be vigilant to efforts by Iran to advance its missile programme. “These measures are part of our response to Iran’s malign activities. These determinations underscore the continuing need for all countries to remain vigilant to efforts by Iran to advance its missile programme,” Pompeo said.