TEHRAN, April 9 (Xinhua) -- Iran's Supreme Leader Mojtaba Khamenei said Thursday that the Iranian people have achieved a "decisive victory" in the war against the United States and Israel, adding that Iran will move the management of the Strait of Hormuz into a new phase.

Khamenei made the remarks in a message carried by Iranian media on the 40th day after the death of former Supreme Leader Ali Khamenei, who was killed in U.S.-Israeli strikes at the start of the conflict.

"We have not sought and do not seek war, but we will not give up on our legitimate rights, and to this end, we consider the entire resistance front as a unified whole," he said.

The supreme leader urged Iran's southern neighbors to "stand in the right place," adding, "We are still waiting for an appropriate response from you to show you our brotherhood and goodwill."

He called the assassination of his predecessor one of the "biggest crimes" by Iran's "enemies" and one of the most "severe public sorrows" in Iran's history.

Iran's people will demand compensation for every damage in the country caused by the attacks of the "aggressors," he said.

He stressed that Iranians must continue their presence in the streets despite upcoming negotiations with the United States, as their "cries" will influence the outcome.

Also on Thursday, massive crowds across Iran attended rallies and ceremonies to mourn former Supreme Leader Ali Khamenei.

In Tehran, the rally, also attended by high-ranking officials such as President Masoud Pezeshkian and cabinet members and ministers, began at 9:40 a.m. local time (0610 GMT), the time when Ali Khamenei, along with a number of his companions and family members, was killed in his office in Felestin (Palestine) Street.

In a gloomy atmosphere, mourners carried pictures of the former leader and current Supreme Leader Mojtaba Khamenei, marching with Iranian and black flags from Jomhouri Square to Felestin Street.

Dressed in black, many marchers held and chanted slogans against the United States and Israel, voiced support for Iran and Lebanon, pledged allegiance to the supreme leader, and demanded a U.S. withdrawal from West Asia.

On Feb. 28, Israel and the United States launched joint attacks on Tehran and several other Iranian cities, killing Iran's then supreme leader, along with senior military commanders and civilians. Iran responded with waves of missile and drone strikes targeting Israel and U.S. assets in the Middle East, and tightened control over the Strait of Hormuz.

A two-week ceasefire reached between Washington and Tehran took effect on Wednesday, with peace talks scheduled to begin later this week in Islamabad, Pakistan.

Mojtaba Khamenei, son of Ali Khamenei, was selected as Iran's new supreme leader on March 8.