By Patricia Zengerle
WASHINGTON (Reuters) - U.S. Senate Democrats and Republicans agreed on Thursday to delay until April 14 the Senate Foreign Relations Committee's vote on legislation that would force President Barack Obama to submit any nuclear agreement with Iran for Congress' approval.
The announcement, which came after an intense lobbying push by Obama and administration officials, gives international negotiators more breathing room as they attempt to meet a late-March deadline for a framework agreement.
Republican Senator Bob Corker, chairman of the Senate Foreign Relations Committee, had said he wanted to have the committee vote next Thursday.
But Democrats balked, reluctant to advance legislation the Obama administration has said could have a "profoundly negative impact" on the nuclear talks with Iran at such a delicate time.
Obama had threatened a veto. The White House said the bill impinged on the president's authority by forcing him to obtain congressional approval, and could prevent a deal from succeeding by removing Obama's ability to temporarily waive sanctions.
The timetable for easing crippling economic sanctions is a major issue in the talks between six world powers and Tehran.
In a joint statement, Corker and Senator Robert Menendez, the top Democrat on the foreign relations panel, said they agreed to mark up after Congress returns from its early-April recess, in order to win the strongest possible support for it.
In a markup, a committee debates legislation and considers amendments before voting on whether to recommend it to the full Senate. Lawmakers and aides say there is a good chance that enough Democrats will join Republicans to give the bill the 60 votes it would need to advance in the Senate.
If passed by the Senate, the legislation would likely move quickly in the House of Representatives, where Republicans hold 245 seats, compared to just 188 Democrats.
Republicans are generally more hawkish about Iran, and skeptical about Obama's negotiations, than the president's fellow Democrats.
If Obama carries through on his veto threat, the bill's backers insist they could marshal the two-thirds of the House and Senate necessary to override the veto. Democratic leaders say it is far too early to tell.
A senior European negotiator said on Thursday that the six world powers were unlikely to reach a framework agreement with Iran in the coming days as the sides are still far apart on key issues.