President Trump urged Congress on Thursday to approve a bill that lets terminally ill patients try experimental treatments, saying that it will give patients the “hope of finding something.”

Trump has made an open push for Congress to approve "right to try" legislation since calling for passage during his first State of the Union speech on Tuesday. Legislation passed the Senate last year and is before the House Energy and Commerce Committee.

“I have known people like this,” Trump said during an address at the Republican retreat in West Virginia Thursday. “They travel all over the world to try and find a cure but it will be years before [drugs] come on to the market.”

"Right to try" lets a patient with a terminally ill disease and no other options bypass the Food and Drug Administration to use an experimental drug.

The FDA already has a program called “compassionate use” that approves access to an experimental drug. The agency has said it approves 99 percent of the roughly 1,000 requests it gets for the program each year.

The Senate bill would bypass the “compassionate use” program.

A patient must have tried all other treatments before pursuing the experimental drug. The product must have completed a phase I clinical trial, which is the first of three trials the FDA requires a new drug to pass.

Trump said "right to try" can help drug companies learn “pretty quickly how effective it is and if it works.”

But that statement illustrates a key hurdle with the idea: drug makers are not required to give the patients the products. The drug company sometimes does not allow access because of concern that any death or injury from the drug could imperil FDA approval.