The US has spoken with its partners, including Japan and the Netherlands, to tighten chip-related exports to China, Jake Sullivan, the White House national security adviser, said on Monday.
The Biden administration aims to cut China off from certain semiconductor chips made anywhere in the world with US equipment, in a bid to slow Beijing's technological and military advances, issuing a series of curbs in October.
Sullivan's comments followed a report by Bloomberg News that the two countries had agreed in principle to join the US-led technology export control, citing people familiar with the matter.
Asked about the report, Japanese Trade Minister Yasutoshi Nishimura said cooperation in export control figured in a telephone conversation he had with US Commerce Secretary Gina Raimondo, but declined to elaborate.
"I cannot go into details as they are diplomatic exchanges, but Japan has been implementing its export control strictly, based on the foreign exchange and foreign trade law in the spirit of international cooperation," he told reporters.
Apart from some US gear suppliers, Japan's Tokyo Electron Ltd and Dutch lithography specialist ASML Holding NV were the two critical players needed to make the sanctions effective, making their governments' adoption of the curbs a key milestone, Bloomberg said.
The new curbs may be announced in the coming weeks, it added.
A spokesperson for Tokyo Electron said the company was in no position to respond since the matter had to do with each country's regulations.
"We intend to keep a close eye on the situation constantly and deal with it appropriately," the spokesperson added.
China is Tokyo Electron's largest market, accounting for 26 percent of its sales of 1.94 trillion yen (S$19 billion) in chip-making equipment for the year that ended in March.
For Japanese chip-testing equipment maker Advantest Corp, China is the second-largest market, after Taiwan.
Orders of 189 billion yen came in from China in the previous business year, or 27 percent of its total.
A spokesperson for the Netherlands foreign ministry declined to comment.