US Secretary of State Antony Blinken said on Wednesday "now is the time" to end the conflict in Gaza, and urged Israel to avoid further escalation with Iran.
Israel is fighting Iran-backed Hamas in Gaza and Hezbollah in Lebanon, and has pledged to hit back against Iran's October 1 missile strike.
In Lebanon, the Israeli military issued a new evacuation call for the south Lebanese city of Tyre on Wednesday, warning of impending operations targeting Hezbollah.
The warning sparked a new exodus from the once vibrant city, which is perched on the Mediterranean coast.
"The situation is very bad, we're evacuating people," said Mortada Mhanna, who heads Tyre's disaster management unit.
"You could say that the entire city of Tyre is being evacuated," said Bilal Kashmar, the unit's media officer.
Blinken's visit to the region is his 11th since the start of the war in Gaza and his first since Israel-Hezbollah violence escalated to all-out war late last month.
The war in Gaza began with Hamas's October 7, 2023 attack on Israel, which resulted in the deaths of 1,206 people, mostly civilians, according to an AFP tally of Israeli official figures.
Israel's retaliatory offensive has killed 42,718 people in Gaza, also mostly civilians, according to figures from the Hamas-run territory's health ministry which the UN considers reliable.
"Since October 7 a year ago, Israel has achieved most of its strategic objectives when it comes to Gaza... Now is the time to turn those successes into enduring, strategic success," Blinken said as he departed Israel, following meetings with Prime Minister Benjamin Netanyahu and other top officials.
On aid to Gaza, Blinken said he saw "progress being made, which is good, but more progress needs to be made and, most critically, it needs to be sustained".
Of Israel's pledge to retaliate for Iran's October 1 missile attack, the US top diplomat said: "It's also very important that Israel respond in ways that do not create greater escalation."
After Israel, Blinken will visit Saudi Arabia, which has put on hold talks towards a normalisation deal with Israel until a Palestinian state is created.
The US diplomat urged Israel to seize what he described as an "incredible opportunity" to move towards a deal with Saudi Arabia.
Previous US efforts to end the Gaza war and contain the regional fallout have failed, as did a bid spearheaded by President Joe Biden and his French counterpart Emmanuel Macron to secure a temporary ceasefire in Lebanon.
In his meeting with Netanyahu on Tuesday, Blinken urged his ally to seize on the killing of Hamas leader Yahya Sinwar in Gaza to work towards a ceasefire.
Sinwar was the architect of the October 7, 2023 attack that triggered the Gaza war.
Hailing his killing, Netanyahu said it did not mean the war was over, though he added that it could be the beginning of the end.
The militants also took 251 hostages back into Gaza. Ninety-seven are still being held there, including 34 the Israeli military has said are dead.
During his meeting with the Israeli premier in Jerusalem, Blinken "underscored the need to capitalise" on the death of Sinwar, US State Department spokesman Matthew Miller said.
This would be done by "securing the release of all hostages and ending the conflict in Gaza in a way that provides lasting security for Israelis and Palestinians alike", he added.
Netanyahu told Blinken that Sinwar's death "could have a positive impact on the return of the hostages", according to a statement from the prime minister's office.
Blinken also pressed for more aid to be allowed into besieged Gaza as concerns rise for tens of thousands of civilians trapped by fighting in the hard-to-reach north.
Israel launched a major air and ground assault in northern Gaza this month, vowing to stop Hamas militants from regrouping in the area.
The only medical facility still partially functioning in the targeted area has "no medicine or medical supplies", warned Kamal Adwan Hospital director Hossam Abu Safia.
"People are being killed in the streets, and we can't help them. Bodies are lying on the streets."
In Lebanon, the Israeli military warned people in parts of Tyre to move out of the areas ahead of operations targeting Hezbollah militants.
Lebanon's official National News Agency meanwhile reported "intense enemy strikes" on several parts of Tyre district on Wednesday.
Hezbollah kept up its attacks on Israel Wednesday, saying it had fired rockets at an Israeli military intelligence base in the suburbs of commercial hub Tel Aviv.
After nearly a year of war with Hamas in Gaza, Israel shifted its focus to Lebanon in late September, vowing to secure its northern border under fire from Hezbollah.
Israel ramped up its air strikes on Hezbollah strongholds around the country and sent in ground troops late last month, in a war that has killed at least 1,552 people since September 23, according to an AFP tally of Lebanese health ministry figures.
On Tuesday, the Israeli army said it had killed the Hezbollah cleric tipped to succeed the group's slain leader Hassan Nasrallah in an air strike three weeks ago.
Hezbollah has not issued a statement confirming Hashem Safieddine's death, but a high-level source close to the group had said that the militant leader had been out of contact since the strikes.
"We have reached Nasrallah, his replacement and most of Hezbollah's senior leadership", Israeli army chief Lieutenant General Herzi Halevi said in a statement.
On Tuesday, the Israeli military again struck the southern suburbs of Beirut, a once densely populated bastion of Hezbollah, after issuing new calls for residents to evacuate the area.
