Arab and Western countries, seeking to head off a major regional conflict in the Middle East, are urging Iran to show restraint after it vowed to attack Israel in retaliation for the killing of Hamas’s political leader in Tehran last week.

The diplomatic push by Jordan, Egypt, Saudi Arabia and Qatar, which have close ties to Washington, came as the United States, France and other countries have also been trying to lower tensions in the Middle East and renew stalled efforts to achieve a cease-fire in the Gaza Strip.

Anxiety across the region has been running high since an explosion in Tehran — widely attributed to Israel — killed Hamas’s political chief, Ismail Haniyeh, on July 31, just hours after an Israeli airstrike in Lebanon killed a top Hezbollah commander, Fuad Shukr.

Iran and Hezbollah in Lebanon have vowed to retaliate for both killings. Prime Minister Benjamin Netanyahu of Israel has promised, in turn, to “exact a heavy price for any act of aggression against us, from whatever quarter.”

Hezbollah, the most powerful of Iran’s proxy forces, and Israel have been trading almost daily fire across the Israel-Lebanon border for months, and Israeli officials have suggested that an invasion of Lebanon could be coming, a prospect the White House and others have tried tamp down. A full-fledged war between Israel and Hezbollah, or one involving Iran directly, would be even more dangerous and destabilizing to the region.

As the region girds for the possibility of a wider war, Jordan’s foreign minister, Ayman al-Safadi, has met twice over the last week with senior Iranian officials, including the newly elected Iranian president, Masoud Pezeshkian, in a rare visit to Tehran.