The surprise Hamas assault on Israel has opened up a new front in the US election campaign as Republicans accuse President Joe Biden of being soft in his defense of Israel and in his handling of Iran.

"I think this is a great opportunity for our candidates to contrast where Republicans have stood with Israel — time and time again –- and Joe Biden has been weak," Ronna McDaniel, chairwoman of the Republican National Committee, said Saturday on Fox News.

Americans will choose a new president and control of Congress in November 2024, with Biden, 80, seeking another term in a race that looks likely to pit him against former president Donald Trump as the Republican candidate.

Trump used the stunning Hamas attack by land, sea, and air at dawn Saturday to target Biden.

"The Israeli attack was made because we are perceived as weak and ineffective and with a very weak leader," he said.

Other Republican presidential hopefuls, like Florida Governor Ron DeSantis and former Vice President Mike Pence, also dismissed Biden as weak.

US stands with Israel

A stern-faced Biden gave a short speech from the White House on Saturday to stress firm US support for Israel.

"Today, the people of Israel are under attack, orchestrated by a terrorist organization, Hamas," Biden said.

"In this moment of tragedy, I want to say to them and to the world and to terrorists everywhere that the United States stands with Israel. We will not ever fail to have their back."

Republicans zeroed in on a recent decision by the Biden administration to release $6 billion in Iranian oil revenue frozen in South Korea in exchange for the release of five Americans who were being held prisoner in Iran.

Tehran is the main sponsor of Hamas, which the United States and other countries classify as a terrorist group.

Senator Rick Scott, for instance, said that in unfreezing that money — it was transferred to a bank account in Qatar for use only for humanitarian purposes — the United States had in effect financed the Hamas attack, which won praise from Iran.

That charge angered the White House, which called it a "shameful lie" and insisted that the money was tightly controlled in how it could be used and none of it had been spent.

A senior administration official speaking to reporters on Saturday accused Republicans of spreading disinformation.

Help from congress

The official, who spoke on condition of anonymity, stressed it was too early to say whether Iran was directly involved in Hamas' large-scale attack, but that there was "no doubt Hamas is funded, equipped and armed by Iran and others."

Aside from the 2024 election, the Republican attacks pose political problems for Biden.

The United States already provides billions of dollars a year for Israel but Biden will need Congress if he wants to send more now that Israel has declared itself at war with Hamas.

That means Biden has to work with the Republicans, who are blocking passage of a yearly budget.

Making matters worse, the House of Representatives is in chaos and limbo now because of the ouster of its speaker, Kevin McCarthy, last week in a revolt by a handful of far right Republicans.

The White House would also like the Senate to approve Jack Lew soon to be the new American ambassador to Israel. His nomination was announced more than a month ago.

This will require goodwill from the Republican minority in that chamber.