Sen. Rand Paul, R-Ky., said Tuesday that he "cannot in good conscience vote to add more to the already massive $20 trillion debt."

Rand Paul tweet: I cannot in good conscience vote to add more to the already massive $20 trillion debt. I promised Kentucky to vote against reckless, deficit spending and I will do just that.

The lawmaker wrote in a post on Twitter that "I promised Kentucky to vote against reckless, deficit spending and I will do just that."

Paul's tweet didn't suggest he would oppose the GOP tax bill due to deficit concerns.

The lawmaker clarified in a follow up tweet that tax cuts "are never the problem."

Paul tweet: Tax cuts — people keeping more of their money — are never the problem. The problem is spending. We should obey our rules, stop the deficit spending, and shrink government.

Senators voted Thursday to approve a two-week spending bill that averted a government shutdown.

It is unclear how Paul's stance will affect negotiations to keep the government running beyond Dec. 22. The temporary spending bill that passed Thursday went through overwhelmingly, with 81 voting in support.