U.S. Senator Marcio Rubio on Wednesday asked the Biden administration to investigate Ford Motor Co.’s plan to partner with PT Vale Indonesia and China’s Zhejiang Huayou Cobalt in a $4.5 billion nickel processing plant in Indonesia.

Rubio, who is the top Republican on the Senate Intelligence Committee, said the venture threatens U.S. national security and asked the Justice, State, Treasury, Commerce, Homeland Security departments as well as the Securities and Exchange Commission to investigate the plan.

Ford had no immediate comment.

Rubio’s letter to Secretary of State Antony Blinken cited Huayou calling the project “one of the flagship projects under the Belt and Road Initiative” when Ford announced the deal in March.

Rubio said the Chinese Belt and Road Initiative is one of the primary mechanisms China “uses to spread its influence around the world and gain control of critical infrastructure and natural resources.”

The investment is Ford’s first in Indonesia and underscores growing appetite among automakers for raw materials used in producing EV batteries, which account for about 40 percent of a vehicle’s sticker price, aiming to cut costs and close the gap on EV market leader Tesla Inc.

Ford’s efforts “to increase the exposure of the U.S. to depend on supply chains controlled by companies subservient to the CCP has grown more brazen and visible over time, especially with regard to critical minerals and EV batteries,” Rubio said a in a letter to Attorney General Merrick Garland.

Indonesia, which has the world’s biggest nickel reserves, has been trying to develop downstream industries for the metal, ultimately aiming to produce batteries and EVs.

Vale and Huayou began construction of the plant in November and commercial operation is expected to start in 2026.

Rubio in March introduced legislation that took aim at Ford’s deal to use technology from Chinese battery company CATL as part of the automaker’s plan to spend $3.5 billion to build a battery plant in Michigan. He had already asked the Biden administration to review the deal to use technology from CATL.

Rubio also wants to block tax credits for EV batteries produced using Chinese technology, in a bid to prevent Chinese companies from benefiting.

Rubio’s request arises as U.S. Senate Democrats renew efforts to stave off competition from China. This push includes planned legislation to boost the country’s ability to face up to the Asian powerhouse on issues from technology to security and threats to Taiwan.

After passing a sweeping bill last year to boost competition with Beijing in semiconductors and other technology, Senate Democratic leader Chuck Schumer and Democratic committee leaders said they would write legislation they hoped to introduce in the next several months to limit the flow of technology to China, deter China from initiating a conflict with Taiwan and tighten rules to block U.S. capital from going to Chinese companies.

Schumer said the bill – dubbed “China Competition 2.0” – would broaden last year’s “Chips and Science” act.

“Today, we are announcing a new initiative, one that will build on this momentum and develop new and significant bipartisan legislation,” Schumer told a press conference.

He said he hoped the bill would be bipartisan, and said Republicans in the Senate had been supportive of some of the ideas proposed for the package. The measure will need Republican support to become law, as Republicans control the House of Representatives.

The desire for a hard line on China is one of the few truly bipartisan sentiments in the perennially divided U.S. Congress, and last year’s legislation passed with overwhelming support from both Democrats and Republicans.

John Thune, the Senate’s No. 2 Republican, however, said the new China initiative would have a hard time getting through Congress, given his party’s concerns about spending and the debt and the size of last year’s bill.

“It would be challenging, and partly because of spending and debt — concerns about too much spending and the impact it’s had on inflation, the way the deficits exploded and ballooned,” Thune said.