Story highlights President Donald Trump called Sen. Rand Paul a "negative force"

The Kentucky Republican said he plans to work with the President

Washington (CNN) President Donald Trump slammed Sen. Rand Paul on Wednesday over the Kentucky senator's open opposition to Republicans' health care plans, though the Kentucky Republican said he's working with Trump to come up with a better proposal.

"Rand Paul is a friend of mine but he is such a negative force when it comes to fixing healthcare. Graham-Cassidy Bill is GREAT! Ends Ocare!" Trump tweeted early Wednesday.

Rand Paul is a friend of mine but he is such a negative force when it comes to fixing healthcare. Graham-Cassidy Bill is GREAT! Ends Ocare! — Donald J. Trump (@realDonaldTrump) September 20, 2017

He added: "I hope Republican Senators will vote for Graham-Cassidy and fulfill their promise to Repeal & Replace ObamaCare. Money direct to States!"

I hope Republican Senators will vote for Graham-Cassidy and fulfill their promise to Repeal & Replace ObamaCare. Money direct to States! — Donald J. Trump (@realDonaldTrump) September 20, 2017

Paul responded to Trump several minutes later: "#GrahamCassidy is amnesty for Obamacare. It keeps it, it does not repeal it. I will keep working with the President for real repeal."

Also currently working with the President to finalize better replacement with cross state purchase of inexpensive insurance. Coming soon! — Senator Rand Paul (@RandPaul) September 20, 2017

He continued: "Also currently working with the President to finalize better replacement with cross state purchase of inexpensive insurance. Coming soon!"