Sen. Bill Nelson (D-Fla.) will be pressing Secretary of Health and Human Services Alex Azar on what's being done to reunite undocumented immigrant children who were separated from their parents under the Trump administration's new "zero tolerance" immigration policy.

Nelson visited an HHS facility in Homestead, Fla., on Saturday after being denied access earlier in the week. He now says he wants to know why he cannot speak to the 70 kids being held at the facility after being separated from their parents.

He also wants to know what is being done to reunite the children with their parents, a process Sen. Marco Rubio (R-Fla.) has also questioned.

"The secretary should have plenty of time between now and his testimony tomorrow to the Finance Committee to find the information he needs to fully answer these questions," Nelson said on the Senate floor. "The American people want to know about these children and when are they going to be reunited."

Azar is appearing on Tuesday before the Senate Finance Committee and is expected take to a second round of questioning about the administration's plan to lower drug prices. Nelson is a committee member.

Nelson is being challenged this year by Gov. Rick Scott for his U.S. Senate seat.

Scott has also slammed President Donald Trump's family separation policy and sought answers from HHS on whether children held there are being given "health, educational or other social services."