Tehran, Iran -- Iran on Friday denied President Donald Trump's claim that a U.S. warship destroyed an Iranian drone near the Persian Gulf. It marked another escalation of tensions between the two countries less than a month after Trump nearly launched an airstrike.

The Iranian military said all its drones had returned safely to their bases and denied there was any confrontation with a U.S. vessel the previous day. The country's elite Revolutionary Guard later released video it claimed proves the U.S. warship didn't destroy one of its drones.

"We have not lost any drone in the Strait of Hormuz nor anywhere else," tweeted Deputy Foreign Minister Abbas Araghchi.

We have not lost any drone in the Strait of Hormuz nor anywhere else. I am worried that USS Boxer has shot down their own UAS by mistake! — Seyed Abbas Araghchi (@araghchi) July 19, 2019

However, Mr. Trump, speaking from the Oval Office Friday, said there was "no doubt" that a U.S. warship destroyed the drone.

Get Breaking News Delivered to Your Inbox

"No doubt about it," he said. "We shot it down."

Secretary of State Mike Pompeo echoed those statements on Friday. "It went down, and the fact that Foreign Minister Zarif either didn't know or lied about it, I can't account for. It happened."

The strategically vital strait is at the mouth of the Persian Gulf and serves as the passageway for one-fifth of all global crude exports, and oil prices ticked upward Friday on the news.

Trump on Thursday said the USS Boxer took action after an Iranian drone closed to within 1,000 yards of the warship and ignored commands to stay away. The president accused Iran of "provocative and hostile" action and said the U.S. acted in self-defense.

Neither Trump nor the Pentagon spelled out how the Boxer destroyed the drone. CNN reported that the ship used electronic jamming to bring it down rather than hitting it with a missile.

On June 20, Iran shot down an American drone in the same waterway, and Trump came close to retaliating but called off an airstrike at the last moment.

The Revolutionary Guard said the Iranian drone on Thursday had been carrying out regular surveillance when the USS Boxer arrived, and transmitted photos of the ship. The Guard said its forces continue to carefully monitor all movements of foreigners - especially "the terrorist forces" of the U.S. and the British in the strait and the Gulf.

The IRG on its website Friday said the drone recorded three hours of video of the USS Boxer and five other vessels Thursday beginning when the ships first entered the Strait of Hormuz. There was no immediate explanation as to how the video proved that no Iranian drone was destroyed.

After Trump pulled the U.S. out of the Iran nuclear deal with world powers last year and imposed economic sanctions against Tehran, the Iranians have pushed back on the military front in recent weeks, with Washington accusing Tehran of threatening American forces and interests in Iraq and in the Gulf.

Iran's foreign minister, Mohammad Javad Zarif, suggested in New York as he arrived for a meeting at the United Nations that Iran could immediately ratify an agreement to allow broader inspections of its nuclear facilities by U.N. inspectors if the U.S. dropped its sanctions.

China urged Washington to consider the offer, calling it "a positive signal that Iran is willing to seek a compromise solution."

The Pentagon said Thursday's incident happened in international waters while the Boxer was entering the Gulf. The Boxer is among several U.S. Navy ships in the area, including the USS Abraham Lincoln, an aircraft carrier that has been operating in the North Arabian Sea for weeks in response to rising tensions.

The Iranians and Americans have had close encounters in the Strait of Hormuz in the past, and it is not unprecedented for Iran to fly a drone near a U.S. warship.

Zarif blamed Washington for the escalation and accused the Trump administration of "trying to starve our people" and "deplete our treasury" through sanctions.

As CBS News senior national security correspondent David Martin has reported this week, the U.S. is trying to convince allies to form a flotilla of warships to secure the shipping channel in and out of the Persian Gulf. About a third of the world's oil supply is moved via tanker from the Persian Gulf through the Strait of Hormuz and out to refineries around the globe every year.