The Israeli military on Friday announced the closure of an evacuation corridor from Gaza City to the southern Gaza Strip that had been opened earlier this week.

According to the army, the route along Salah al-Din road would remain available for civilians until noon Friday.

"From this moment, Salah al-Din Road is closed for southbound travel. The Israeli Defense Forces will continue to operate with unprecedented and intense force against Hamas and other terrorist organizations," the military's Arabic-language spokesman, Avichay Adraee, said in a post on X addressed to the residents of Gaza City.

The spokesman added that the only possible route south was via Al-Rashid Street, urging residents to "take this opportunity" to join those "who have already moved to the humanitarian area in the south."

Israeli media reported that about 450,000 people, or 45 percent of those who were in Gaza City on August 10 - when Israel announced plans to take control - had already left Gaza City as of Thursday.

A day after Israel announced the launch of its ground offensive to seize control of Gaza's main urban center, tanks had moved short distances towards the city's central and western areas from three directions, but no major advance was reported.

An Israeli official said military operations were focused on getting civilians to head south and that fighting would intensify over the next month or two.

The official said Israel expected around 100,000 civilians to remain in the city, which would take months to capture, and said the operation could be suspended if a ceasefire was reached with the Hamas militant group.

The prospects of a ceasefire appear remote after Israel attacked Hamas political leaders in Doha last week, infuriating Qatar, a co-mediator in ceasefire talks.

Defying global criticism of the attack, including a rebuke by Israel's stalwart ally, the United States, Prime Minister Benjamin Netanyahu has said Israel would strike Hamas leaders anywhere.

The U.S., though disapproving of the Qatar strike, on Thursday vetoed a draft United Nations Security Council resolution that would have demanded an immediate, unconditional and permanent ceasefire in Gaza and that Israel lift all restrictions on aid deliveries to the Palestinian enclave.

The text, drafted by the elected 10 members of the 15-member council, would also have demanded the immediate, dignified and unconditional release of all hostages held by Hamas and other groups.

It received 14 votes in favor. It was the sixth veto cast by the U.S. in the Security Council over the nearly two-year conflict between Israel and Palestinian militants Hamas.

The United Nations, aid groups and foreign governments have condemned Israel's offensive and the proposed mass displacement.

In a separate response to the Gaza conflict in general, a UN Commission of Inquiry concluded on Tuesday that Israel had committed genocide in Gaza. Israel called the assessment "scandalous" and "fake."

(With input from agencies)