US President Donald Trump declared that Iran has been "decimated" by the US in a post on Truth Social on Friday.

"If you read the Failing New York Times, you would incorrectly think that we are not winning," Trump said.

"Iran’s Navy is gone, their Air Force is no longer, missiles, drones, and everything else are being decimated, and their leaders have been wiped from the face of the earth. We have unparalleled firepower, unlimited ammunition, and plenty of time - Watch what happens to these deranged scumbags today."

Iran had been killing innocents all over the world for 47 years, Trump wrote, saying that it was an "honor" to be killing them now.

Additionally, Trump said he believes Iran's new Supreme Leader, Mojtaba Khamenei, is still alive "in some form," during an interview with FOX's Brian Kilmeade scheduled to air on Friday.

A Thursday message attributed to Khamenei was read out by a newscaster on Iranian state television while a photo of the supreme leader was shown, but there have not been any signs of life from Khamenei since his appointment.

Trump also claimed during the interview that "Iran had thousands of missiles pointed at all these Middle Eastern countries for the last four months," and that "They were going to take over the Middle East, they were going to control it all, UAE, Qatar, Oman, and Saudi Arabia."

"All these nations were afraid of Iran, and they are not anymore. But they had reason to be afraid. We have knocked the hell out of them like no other nation could and they still have remnants left," Trump said, adding that countries should travel freely through the Strait of Hormuz and "show some guts," since the US "completely destroyed" Iran's navy.

Trump also said the United States would escort vessels through the Strait of Hormuz if needed, adding in a Fox News interview that aired on Friday that the US would strike Iran "very hard over the next week."

Asked about helping oil tankers pass through the key shipping strait, Trump said: "We would do it if we needed to. But, you know, hopefully things are going to go very well. We're going to see what happens." He gave no other details.

"We're going to be hitting them very hard over the next week," he added in the interview with Fox's Brian Kilmeade that aired in part on its Fox & Friends program. 

His comments come as the United States and other countries face spiking oil and gas prices with the US-Israel war entering its 14th day, with oil prices hovering near $100 a barrel on Friday.

Iran team attending FIFA world cup would be inappropriate, Trump says

Several other posts were made by Trump on Friday about the upcoming FIFA World Cup, set to be co-hosted by the United States.

One, about the possibility of the Iran soccer team being included, declared that Trump didn't believe it was appropriate for the team to attend, "for their own life and safety."

In another post, Trump expressed confidence that the event would be a success, claiming that it would be "the Greatest and Safest Sporting Event in American History."

Several prominent international figures have discussed boycotting the World Cup over the Trump administration's numerous controversial actions.

Joseph Sepp Blatter, former FIFA president, backed a proposed boycott of World Cup matches in the United States in January, while Mark Pieth, a Swiss attorney specializing in white-collar crime and anti-corruption who previously chaired the Independent Governance Committee that oversaw FIFA's reform efforts, told fans to "Stay away from the USA!"

The Associated Press reported that concerns from the international soccer community about the United States primarily stem from Trump's expansionist stance on Greenland, as well as travel bans and aggressive tactics in dealing with migrants and immigration enforcement protesters in American cities, particularly Minneapolis. 

Shir Perets and Shoshana Baker contributed to this report.