Sen. Rand Paul on Sunday indicated he may not support President Trump's nominee to replace former Attorney General Jeff Sessions because of some of the "troubling" decisions he's made.

Paul told NBC News he hasn't made a decision yet on William Barr, in part because of his past positions on Patriot Act surveillance and civil asset forfeiture. "I haven't made a decision yet on him. But I can tell you that the first things I've learned about him being for more surveillance of Americans is very, very troubling," said Paul, R-Ky.

"I'm concerned that he's been a big supporter of the Patriot Act, which lowered the standard for spying on Americans, and even went so far as to say that the Patriot Act was pretty good but we should go much further," Paul said.

"I'm disturbed that he's been a big fan of taking people's property, civil asset forfeiture, without a conviction. Many poor people in our country have cash taken from them and then the government says, 'Prove to us where you got the cash and then you can get it back,' but the burden is on the individual. It's a terrible thing called civil asset forfeiture and he's a big fan of that."

Trump announced Friday his intention to nominate Barr, who led the Justice Department during former President George H.W. Bush's administration from 1991-1993. If confirmed by the Senate, Barr would be responsible for overseeing the conclusion of special counsel Robert Mueller's federal Russia investigation into possible ties between the 2016 Trump campaign and Moscow.

Barr is expected to be considered next year, when Republicans will have a 53-47 majority. Sen. Marco Rubio, R-Fla., told CBS News Sunday he did not know whether he would support Barr yet as he had not "even begun to review his qualifications or his record in the past,” but he hoped that he could. Barr can still be confirmed even if he loses three Republican votes, in which case Vice President Mike Pence would be able to break a 50-50 tie.