The U.S. Treasury on Friday announced sanctions against 10 individuals and companies, including several in China and Hong Kong, over accusations they aided Iran's efforts to secure weapons and the raw materials needed to build its Shahed drones and ballistic missiles.

The Treasury move, first reported by Reuters, comes days before U.S. President Donald Trump plans to travel to China for a meeting with President Xi Jinping and as efforts to end the war with Iran have stalled.

In a statement, Treasury said it remained ready to take economic action against Iran's military industrial base to prevent Tehran from reconstituting its production capacity.

Treasury said it was also prepared to act against any foreign company supporting illicit Iranian commerce, including airlines, and could impose secondary sanctions on foreign financial institutions that aid Iran's efforts, including those connected to China's independent "teapot" oil refineries.

Brett Erickson, managing principal at Obsidian Risk Advisors, said Treasury's actions were aimed at cracking down on Iran's ability to threaten ships operating in the Strait of Hormuz and regional allies.

Iran shut the Strait of Hormuz, a narrow chokepoint between Iran and Oman through which a fifth of the world's ​crude oil and liquefied natural gas passes, after the U.S. and Israel attacked a large number of targets in Iran on February 28.

Shipping through the crucial waterway has ground to a near ⁠halt since the war began, sending energy prices sharply higher.

Iran is a major drone manufacturer and has the industrial capacity to produce around 10,000 a month, according to the British government-fund Centre for Information Resilience.

Erickson said the sanctions were still narrowly focused, giving Iran more time to adapt and reroute procurement to other suppliers. Treasury was also not yet going after Chinese banks that were keeping Iran's economy going, he added.

The companies facing sanctions include:

• China-based Yushita Shanghai International Trade Co Ltd for facilitating acquisition efforts for Iran to purchase weapons from China.

• Dubai-based Elite Energy FZCO for transferring millions of dollars to a Hong Kong company to aid the procurement effort.

• Hong Kong-based HK Hesin Industry Co Ltd and Belarus-based Armory Alliance LLC for working as intermediaries in the procurements.

• Hong Kong-based Mustad Ltd for facilitating weapon procurement by Iran's Islamic Revolutionary Guard Corps.

• Iran-based Pishgam Electronic Safeh Co for procuring motors used in drones.

• China-based Hitex Insulation Ningbo Co Ltd for supplying materials used in ballistic missiles.

  -Andrea Shalal/Reuters