White House aide Marc Short declined to say Thursday whether the Republican tax plan has enough votes to pass Congress, noting that lawmakers still have to mark up the measure.

"That's a question I can't answer today, because we're still working through the markup process," Short, the White House director for legislative affairs, said on CNN'S "Situation Room."

"There needs to be final legislation," he added.

Short pointed to an expected vote on a budget resolution next week in the Senate. The resolution will need to pass in order for the Senate to consider a tax bill under special rules allowing them to approve it on a simple majority, party-line vote.

The Senate version of the bill would allow for $1.5 trillion in tax cuts over the next decade.

A budget resolution passed the House last week, but the two chambers would need to come to an agreement to merge their blueprints.

A top Republican on the House Ways and Means Committee said Wednesday that lawmakers plan to move quickly on a tax-reform bill once Congress adopts a budget resolution.

"Our administration feels what's most important right now is to get the economy growing again," Short said.