A rudderless Congress on Monday heard from a former speaker, Congressman Kevin McCarthy, who is calling on both that body and the White House to move quickly in support of Israel. His appearance has reignited speculation that Mr. McCarthy may seek re-election to the speakership this week.

His return to the fray came just hours before Republicans were scheduled to huddle behind closed doors and attempt to coalesce around a new speaker. Congressman Steve Scalise and his more hardline colleague, Congressman Jim Jordan, have both announced that they are running for the office.

Mr. McCarthy on Monday denounced the small group of Republicans who voted to remove him from the speakership, as well as Democrats who have always opposed him. 

At the press conference, Mr. McCarthy sidestepped questions about whether he would seek the speaker’s office again, in light of recent developments, repeatedly saying that “the conference decides that.” Ahead of Mr. McCarthy’s appearance, he told radio host Hugh Hewitt, “Whatever the conference wants, I will do.” 

Mr. McCarthy did, though, acknowledge that the House would be unable to approve any material aid to Israel until there was a speaker. He suggested that the speaker pro tempore, Congressman Patrick McHenry, might be able to bring a vote on a resolution in support of Israel.

“Unfortunately the House can do nothing without a speaker,” Mr. McCarthy said, posing the question, “Is our conference just going to select someone to throw them out in another 35 days?”

According to reporting by Axios and Politico, there are concerns among Biden administration officials that a lack of House leadership could delay the legislative approval of any aid package. Yet there are some potential moves that the Biden administration could take without approval from the House in the immediate future, according to Mr. McCarthy.

One potential option available to the White House, Mr. McCarthy said, is the release of American ammunition stockpiles stored in Israel. Mr. McCarthy also said the president can refreeze the $6 billion in Iranian assets that were supposed to be unfrozen in exchange for five American hostages. 

Although it’s unclear if the White House could supply such munitions without the approval of Congress, Mr. McCarthy called on the Biden administration to ensure that any aid package includes munitions for the Iron Dome defense missile defense system.

The Biden administration announced before noon Monday that President Biden would not be making any public appearances or statements about American aid to Israel for the remainder of the day.

Mr. Biden’s retreat from the public eye during much of the violence in Israel over the weekend drew scorn from the former speaker Monday. “To the president, turn off the barbecue and speak to the American people to be the leader the world is looking for,” Mr. McCarthy said, referencing a White House staff event Sunday.

In a statement to Fox News responding to Mr. McCarthy’s comment, the White House said, “President Biden has been consistently engaged in supporting Israel as they defend themselves against these brutal terrorist attacks,” citing a call with Prime Minister Netanyahu and orders given by the president to provide aid to the Israeli military, which occurred before the staff event at the White House.

The White House spokesman added that the staff barbecue was a “long-scheduled event” and the date was chosen so White House staff could bring their families, adding, “They deserve recognition, and no small, petty comments from partisan media or elected officials change that.”

Mr. McCarthy’s appearance Monday reignited speculation that he is seeking to return to the speakership, even as he insisted that he would leave it up to the Republican conference to decide.

Some House members are pushing to reinstate Mr. McCarthy as speaker, given the rapidly evolving situation, citing concerns that another battle over the speakership will delay any aid. “A short window is all we need in the House to reinstate Kevin McCarthy and change the rule,” Congressman John Duarte told Politico.

It’s not clear whether any of the House Republicans who voted against Mr. McCarthy are willing to support him when the House returns to session this week or if enough Democrats might be willing to support him for speaker.

Congressman Matt Gaetz and Congresswoman Nancy Mace have endorsed Mr. Jordan for the speakership, as has President Trump. The current the majority leader, Mr. Scalise, has pitched himself as a unity candidate for Republicans and enjoyed the support of some former supporters of Mr. McCarthy, though Axios reports Mr. McCarthy himself had backed Mr. Jordan prior to violence breaking out at Israel.

In the absence of a speaker, the minority leader, Congressman Hakeem Jeffries, has been coordinating with the administration to schedule a briefing of the full House this week. On Sunday, Mr. Jeffies called for an end to “chaos and extremism in Congress,” adding, “We must take an enlightened bipartisan path forward.”