Chicago | Reuters — The U.S. government panel that reviews foreign acquisitions should assess the impact on domestic food security from state-owned China National Chemical Corp’s planned US$43.1 billion acquisition of Swiss seeds and pesticide maker Syngenta AG, four U.S. senators said in a letter Thursday.

The letter, sent to Treasury Secretary Jacob Lew, also said the U.S. Department of Agriculture (USDA) and the U.S. Food and Drug Administration (FDA) should be included in the review.

Lew chairs the U.S. Committee on Foreign Investment in the United States (CFIUS), which comprises representatives from 16 U.S. agencies including Treasury, Homeland Security and Defense. The USDA and FDA are not formally included in the review process, according to the letter.

Last month, Syngenta said it would make a voluntary filing with the committee “even though no obvious national security concerns were identified during due diligence.”

The company, which generates nearly a quarter of its revenue from North America, is the biggest seller of pesticides in North America and also a key player in seeds. Its U.S. headquarters are in North Carolina. It has other facilities in the state, as well a presence in California, Delaware, Iowa and Minnesota, among others.

The letter was signed by Senate agriculture committee Republican members Chuck Grassley and Joni Ernst of Iowa and Democrats Debbie Stabenow of Michigan and Sherrod Brown of Ohio.

In 2013, the foreign investment committee cleared the way for China-based Shuanghui International Holdings to buy meat company Smithfield Foods.

— Reporting for Reuters by Tom Polansek.