Sen. Chuck Grassley is all for importing drugs to drive down prices. He just wants the Trump administration to stop warning foreign manufacturing plants that FDA inspectors are on their way—particularly in India and China.

In a letter sent Wednesday to Health and Human Services Secretary Alex Azar and FDA acting Commissioner Norman Sharpless, the Republican senator from Iowa said surprise inspections were needed as the pharmaceutical production sites make most of the ingredients for drug products sold in the U.S.

"As you are aware, I believe that drug importation will help to reduce drug costs for American consumers and patients," Grassley wrote. "However, I have also noted that my position is predicated on the FDA ensuring the safety and efficacy of those drugs."

About 80% of active pharmaceutical ingredients used in U.S. pharmaceuticals are manufactured overseas with the majority of APIs produced in China and India, yet the FDA only inspected one in five registered human drug production plants abroad last year, Grassley said.

As the administration opens the door to foreign imports, that needs to change, he said. "I strongly encourage the administration’s demonstration projects to include unannounced inspection in foreign manufacturing facilities to determine whether they meet the required active pharmaceutical ingredients and drug quality and safety standards to include sufficient record-keeping, testing and protections against counterfeiting," Grassley wrote.

In 2014 the FDA unveiled a pilot program in India, the senator noted, that cut out advance notice of an inspection in lieu of either short notice or an unannounced visit. That program also provided that FDA inspectors arrange their travel through U.S. embassies versus FDA offices or manufacturer-arranged travel so there was more secrecy ahead of an inspection.

Under that program, the FDA saw a 60% increase in the number of warnings it issued to manufacturers, he said. The pilot program ended in 2015.

Grassley’s call comes in the wake of news that the Pentagon is eyeing China’s API production as a potential health and security issue. 

Following a series of FDA recalls of "sartan" active ingredients used in making generic blood pressure medications, the Defense Health Agency said it was scrutinizing increased Chinese production of the API behind a range of blood pressure drugs that include losartan and valsartan as a health threat to military personnel who use the drugs.