Fifteen U.S. Senators on Thursday raised questions about government oversight of the proposed purchase of Smithfield Foods Inc by Chinese food company Shuanghui International.

The deal will undergo a national security review by the Committee on Foreign Investment in the United States.

In a letter to Treasury Secretary Jack Lew, 15 senators said that the U.S. Department of Agriculture and the Food and Drug Administration should be included in the CFIUS process so that food supply and food safety issues are properly considered.

Those agencies are not typically involved in CFIUS deliberations.