US Secretary of State John Kerry on Wednesday welcomed a compromise with Congress on giving lawmakers a say on any final deal on Iran’s nuclear program.

US Secretary of State John Kerry on Wednesday welcomed a compromise with Congress on giving lawmakers a say on any final deal on Iran's nuclear program.

Kerry said the measure approved Tuesday by the Senate Foreign Relations Committee, which raises the threshold for critics in Congress to block any accord with Tehran, made him "confident" ahead of a June 30 deadline.

"Yesterday there was a compromise reached in Washington regarding congressional input," he told reporters in Germany at a G7 foreign ministers' meeting.

"We are confident about our ability for the president to negotiate an agreement and to do so with ability to make the world safer."

In a display of bipartisan cooperation on what has been a divisive issue, the Senate Foreign Relations Committee voted 19-0 in favor of allowing lawmakers to review and potentially reject the final accord.

However under the legislation, which now heads to a full Senate debate and vote, the total review period would be reduced to 52 days, from the 60 days in earlier drafts.

Contentious language obliging President Barack Obama to certify to Congress that Iran was “not engaging in terrorism” was also removed from the bill.

Global powers must resolve a series of technical issues by a June 30 deadline for a final deal, including the steps for lifting sanctions on Iran.

Many of the countries involved in the Iran negotiations were attending the two-day G7 meeting in the northern city of Luebeck, which will also address a range of global crises including Ukraine, Yemen and the threat posed by the Takfiri group, ISIL.