Ukraine and Israel Aid Bill Stalled in Senate as Divided G.O.P. Demands Changes

Senators raced on Thursday to revive a sweeping emergency national security aid bill for Ukraine and Israel that has stalled yet again on Capitol Hill amid Republican resistance.

Republicans who voted to block the measure on Wednesday were again withholding their support for moving forward with the bill, which includes $60.1 billion for Ukraine, $14.1 billion for Israel and $10 billion in humanitarian aid. They demanded the chance to propose changes, including adding border restrictions — just one day after having blocked a version of the legislation that included a bipartisan package of border restrictions.

Feuding over what modifications to seek, Republicans were huddling behind closed doors in the Capitol on Thursday morning to iron out their disputes.

Senator Chuck Schumer, Democrat of New York and the majority leader, who had planned a quick vote on the foreign aid-only measure on Wednesday, said he hoped it could now take place on Thursday afternoon. The bill would need 60 votes to advance, which would require the support of at least 10 Republicans.

The impasse was the latest manifestation of discord that has roiled the G.O.P. and ground efforts to pass national security spending bills in both chambers of Congress to a standstill, as Republicans clash over how to address international crises without angering their party leader and presumptive presidential nominee, former President Donald J. Trump.

Senate Republicans had initially signaled early Wednesday that they were likely to support moving forward with a clean foreign aid bill without border provisions as long as they had opportunities to propose changes, terms that Mr. Schumer agreed to in principle. Leaders on both sides were optimistic that they would have enough backing to speedily advance the measure.