"I don't have the feedback from constituencies who will not have had enough time to review the Senate bill", Johnson said.
As Republicans scrambled today to wrangle enough votes to pass health care reform legislation, US President Donald Trump lashed at Democrats accusing them of "obstruction" over the bill.
Johnson, elected in 2010 running against Obamacare, also said on NBC's "Meet The Press" program that the debate on revising health care has not been based on facts.
Mike Huckabee (R) heavily criticized Hillary Clinton and Chuck Schumer (D-N.Y.), the Senate minority leader, for their dramatic attacks on the Republican Senate leadership's health care bill.
But in his interview on Sunday, Trump seemed confident in the contents of the Senate's bill, as well as its passage - although he predicted some changes to placate the senators that are now not supporting the legislation. "But we won't get one Democratic vote - not one".
President Donald Trump is bemoaning what he calls "the level of hostility" that he says has stymied bipartisanship in Washington.
Trump tells "Fox and Friends" that "we've a very good plan".
But that optimism runs counter to the public opposition of five Republican senators so far to the Senate GOP plan that would scuttle much of former President Barack Obama's health law.More news: Three A's players knock first Major League Baseball homers in the same game
Johnson's Democratic counterpart representing Wisconsin, Sen. "They're not addressing the root cause", he said, referring to rising health care costs.
In the narrowly divided Senate, defections from just three of the 52 Republican senators would doom the legislation.
The leader of the minority Senate Democrats, Senator Charles Schumer, said Sunday that Republicans have "at best a 50-50 chance" of approving their Senate proposal.
Besides the five who have announced their outright opposition, several other GOP senators - both conservatives and moderates - have declined to commit to the new overhaul.
Sen. Susan Collins, R-Maine, said seven to eight other senators including herself were troubled by provisions that she believes could cut Medicaid even more than the House version. She said she intends to wait for a Congressional Budget Office analysis before making a decision.
"It's hard for me to see the bill passing this week", Collins said. The bill, titled the Better Care Reconciliation Act, would scale back numerous Obamacare mandates, regulations and taxes, but would keep much of the basic framework in place.
Collins spoke on ABC's "This Week". "But I think they're going to get there", Trump said of Republican Senate leaders.