JERUSALEM — Israel’s prime minister was meeting with President Putin at Moscow Saturday.

Prime Minister Bennett’s office confirmed the meeting at the Kremlin, which came just days after Mr. Bennett spoke over the phone with both Russian and Ukrainian leaders.

Mr. Bennett’s office said he departed early Saturday morning for Moscow, accompanied by a Russian-speaking Cabinet minister, Zeev Elkin. Both men are observant Jews and wouldn’t normally travel on the Sabbath. An exception was made because the trip could result in lives being saved.

Israel is one of the few countries that has good working relations with both the Russians and the Ukrainians. The country has delivered humanitarian aid to Ukraine, but also maintains ties with Moscow to make sure that Israeli and Russian warplanes do not come into conflict in neighboring Syria.

Also Saturday, President Zelensky made a “desperate plea” to U.S. senators to help his country get more planes to help the country fight the Russian invasion.

Mr. Zelensky made the request on a call joined by more than 300 people, including senators, some House lawmakers, and aides.

The Senate majority leader, Chuck Schumer, a Democrat of New York, said in a statement that Mr. Zelensky made a “desperate plea for Eastern European countries to provide Russian-made planes to Ukraine.”

Mr. Zelensky told senators he needs planes and drones more than other security tools, according to a senior Senate aide granted anonymity to discuss the private meeting.

The U.S. Congress also is working on a $10 billion package of military and humanitarian aid, and Mr. Schumer told Mr. Zelensky that lawmakers hope to send it quickly to Ukraine, the person said.

Meanwhile, the office of President Macron said France will propose concrete measures to ensure the safety and security of Ukraine’s five main nuclear sites. The safeguards will be drawn up on the basis of International Atomic Energy Agency criteria, a statement from the French presidency said.

The announcement comes after Russian troops seized the Zaporizhzhia nuclear plant — the country’s largest — in the southeastern city of Enerhodar. The attack caused global alarm, evoking memories of the world’s worst nuclear disaster, at Ukraine’s Chernobyl.

The International Atomic Energy Agency said no radiation spikes were detected, however. The chief of the U.N. agency, Rafael Mariano Grossi, said a Russian “projectile” hit a training center, not any of the six reactors.