U.S. military action has so far failed to halt attacks by Iran-backed groups on Washington's forces in the Middle East and shipping in the Red Sea, with the threats persisting despite recent heavy air strikes.

The attacks by militants -- which the armed groups that claim them say are driven by the Israel-Hamas war -- have been launched from or hit four different countries, posing a multi-front challenge for the United States, which aims to curb the unrest while avoiding direct conflict with Iran.

French President Emmanuel Macron on Wednesday described the October 7 attack by Hamas on Israel as the "biggest anti-Semitic massacre of our century" as he hosted a ceremony paying tribute to the French victims.

He described the attack by the Palestinian militant group as "barbarism... which is fed by anti-Semitism and propagates it," vowing also not to give in to "rampant and uninhibited anti-Semitism."

Israel has said it was examining Hamas's response to a plan to halt nearly four months of fighting in Gaza, after key mediator Qatar said the Palestinian militants had given a "positive" reply to the proposed agreement.

U.S Secretary of State Antony Blinken, on his fifth tour of the region since the war broke out in October, arrived in Israel to discuss what he called an "essential" agreement.

Saudi Arabia has told Washington it will not establish ties with Israel until an independent Palestinian state "is recognised", the Gulf kingdom's foreign ministry said in a statement on Wednesday.

"The Kingdom has communicated its firm position to the U.S. administration that there will be no diplomatic relations with Israel unless an independent Palestinian state is recognised on the 1967 borders with East Jerusalem as its capital," read the statement published by the official Saudi Press Agency.

U.S. Secretary of State Antony Blinken met with Israeli leaders on Wednesday after Hamas put forward a detailed plan for a new cease-fire and hostage release deal, but both sides remain dug in on thus far elusive goals as the war enters its fifth month.

Hamas laid out a three-phase plan to unfold over 4 1/2 months, responding to a proposal drawn up by the United States, Israel, Qatar and Egypt. All hostages would be released in exchange for hundreds of Palestinians imprisoned by Israel, including senior militants, and an end to the war.

Qatar said Tuesday that Hamas has delivered a "positive" response to a proposal to free hostages in return for pausing the Gaza war, which U.S. Secretary of State Antony Blinken will take to Israel.

"We have received a reply from Hamas with regards to the general framework of the agreement with regards to hostages. The reply includes some comments, but in general it is positive," Qatari Prime Minister Mohammed bin Abdulrahman Al-Thani said after meeting Blinken in Doha.

Argentina's President Javier Milei arrived in Israel on Tuesday and immediately announced a plan to relocate his country's embassy to Jerusalem.

"My plan is to move the embassy to West Jerusalem," the libertarian head of state told Israeli Foreign Minister Israel Katz on the tarmac of the airport near Tel Aviv.

Bulgarian Transport Minister Georgy Gvozdeykov said Tuesday that the crew of the Galaxy Leader cargo ship captured by Yemen's Houthi rebels in November are "safe and sound" and will shortly return to Bulgaria.

"The information we have ... on the sailors of the Galaxy Leader captured in the Red Sea is that they are well, safe and sound and are staying in a hotel," the minister told private Bulgarian television station bTV.

By Benjamin Case, Arizona State University

As the war in the Gaza Strip enters its fourth month, on the surface it might seem like possibilities for long-term, peaceful solutions are impossible. Even before the Oct. 7, 2023, attack on southern Israel by Hamas-led forces from Gaza, many analysts were already declaring the idea of a two-state solution dead.

Russia has accused the United States of aggression against Iraq and Syria aimed at preserving its global dominance and salvaging the Biden administration's "image" ahead of U.S. elections. The U.S. retorted that its military response to unjustified attacks by Iranian-backed proxies against American forces is not only legal but will continue.

The exchange came at a contentious U.N. Security Council meeting called by Russia, Syria's closest ally, where both countries also said they did not want an escalation and spillover of the Israel-Hamas war. Many council members expressed fears of a growing Mideast conflict and urged de-escalation and stepped-up peace efforts.