Secretary of State John Kerry said on Sunday that he will go to Capitol Hill this week to brief congressional members about the Obama administration’s Iran nuclear deal and urged opponents to “hold their fire” until they see a final deal later his year.

The administration has since reaching the April 1 deal urged the Senate not to vote on legislation that would require congressional approval to ease sanctions on Iran, as Tehran curtails its uranium-enrichment program. And President Obama has vowed to veto such legislation, if passed.

Kerry said he would brief House members on Monday and senators on Tuesday. The Senate Foreign Relations Committee is set to take up the legislation on the same day.

The administration should be free to negotiate without interference until the June 30 deadline for a final agreement, Kerry said on CBS' "Face the Nation."

"We've earned the right to be able to try and complete this without interference, and certainly without partisan politics," Kerry said.

The Senate bill, by committee chairman Sen. Bob Corker, R-Tenn., and Sen. Bob Menendez, D-N.J., would give Congress a 60-day review and a say on any deal.

Under the bill as currently written, Obama could unilaterally lift or ease any sanctions that were imposed on Iran through presidential action. But Congress could block the president from providing Iran with any relief from congressional sanctions.

Senators on both sides of the issue have introduced more than 50 amendments to the legislation.

Opponents of the deal say they don’t know the exact details because both sides are giving different interpretations. Among their concerns are the guidelines for inspecting Iran's nuclear sites and when the sanctions will be lifted.

Kerry told NBC’s “Meet the Press” the United States won’t sign a bad or ambiguous deal.

“If there’s not an understanding, we won’t sign it,” he said.

The Associated Press contributed to this report.