White House Office of Budget and Management Mick Mulvaney on Monday rejected Republican Sen. Lindsey Graham's claim White House senior policy adviser Stephen Miller is dictating the administration's immigration policy.

"The president makes the decisions about the immigration in the White House. Period. End of story," Mulvaney said when asked bout Graham's claim.

When asked if Lindsey Graham was wrong, Mulvaney said, "I believe that Lindsey is. Yes, sir."

Graham, a South Carolina senator who has acted as a mediator in discussions between the White House and Congress, told reporters over the weekend that Miller has repeatedly squashed proposals.

“I've talked with the president. His heart is right on this issue. I think he's got a good understanding of what will sell,” Graham said. “And every time we have a proposal it is only yanked back by staff members. As long as Stephen Miller is in charge of negotiating immigration, we are going nowhere. He has been an outlier for years. There's a deal to be had.”