Samsung and SK Hynix will be able to ship U.S. semiconductor manufacturing equipment indefinitely to their Chinese factories, South Korea’s Yonhap News Agency reported.

Choi Sang-mok, Seoul’s senior presidential secretary for economic affairs, said on Monday the U.S. government has already notified the two companies of its decision, which takes effect immediately.

The U.S. previously granted Samsung Electronics and SK Hynix one-year waivers to import advanced tools for their China factories. It is expected that the waivers will expire this month.

Choi said that the U.S. government’s decision resolves the most important trade issue for semiconductor companies.

As a result of this latest development, Samsung and SK Hynix’s concerns about their chip production in China have been alleviated.

Samsung manufactures 40% of its flash memory chips (NAND) in China, according to a Fitch report. As well as DRAM chips, NAND chips, and 40%-50% of SK Hynix’s NAND capacity are made by this company.

According to TrendForce data, Samsung Electronics and SK Hynix are the world’s biggest and second-largest DRAM memory chipmakers, with Micron trailing in third.

In October, the U.S. implemented sweeping rules limiting China’s ability to manufacture and obtain high-tech semiconductor chips. As a result, Washington is concerned that China will use these high-tech chips for military purposes.