Washington (CNN) President Donald Trump said Thursday that the USS Boxer downed an Iranian drone that came within 1,000 yards of the Navy ship and ignored "multiple calls to stand down" -- marking yet another escalation in the already tense situation playing out between Washington and Tehran.

Speaking at the White House, Trump said the drone was "threatening the safety of the ship and the ship's crew" in the Strait of Hormuz and was "immediately destroyed."

The drone was destroyed using electronic jamming, according to a US defense official.

The crew of the Boxer took defensive action after the drone came within a threatening distance of the US ship, the official said.

A US Navy official told CNN that there were several other interactions between the US warship and Iranian military forces prior to the downing of the drone.

An unarmed Iranian navy Bell 212 helicopter flew close to the Boxer, coming close to the ship's deck before a US helicopter was able to "chase" it away, the official said.

Several Iranian speed boats were in the vicinity as well and maintained a safe distance, but a larger Iranian vessel came as close as 500 yards to the Boxer, a distance that typically merits a warning from US naval vessels, they added.

In response, US helicopters flew between the Iranian ship and the Boxer "to warn it away." They also followed an Iranian aircraft, assessed to be a Y-12 surveillance plane.

"This is the latest of many provocative and hostile actions by Iran against vessels operating in international waters," Trump said. "The United States reserves the right to defend our personnel, our facilities and interest and calls upon all nations to condemn Iran's attempts to disrupt freedom of navigation and global commerce."

He called on other countries to condemn Iran's action and protect their own vessels.

Denials from Tehran

Iran's Minister of Foreign Affairs Mohammad Javad Zarif told reporters at the United Nations in New York Thursday that "we have no information about losing a drone."

On Friday, Tehran's top military spokesman dismissed Trump's claims as "delusional" and said that all Iranian drones were back "safe and sound" at their bases, reported the country's semi-official MEHR News agency.

"Contrary to Trump's delusional and groundless claim, all drones belonging to the Islamic Republic of Iran in the Persian Gulf and the Strait of Hormuz, including the one mentioned by the US President, have returned to their bases safe and sound after carrying out their scheduled surveillance and control operations," Brigadier General Abolfazl Shekarchi said, according to MEHR News.

Iran's Deputy Foreign Minister Seyed Abbas Araghchi also denied that an Iranian drone has been downed and tweeted Friday that he was "worried that USS Boxer has shot down their own UAS by mistake!"

Relations between Iran and the United States have deteriorated since May 2018, when Washington chose to leave the 2015 nuclear deal the Iranian regime negotiated with world powers and reimpose crippling sanctions on Iran's economy.

U.S. Navy amphibious assault ship USS Boxer (LHD 4) transits the East Sea on March 8, 2016 during Exercise Ssang Yong 2016.

The Pentagon released a statement about the drone downing shortly after Trump's comments.

"At approximately 10 a.m. local time, the amphibious ship USS Boxer was in international waters conducting a planned inbound transit of the Strait of Hormuz. A fixed wing unmanned aerial system (UAS) approached Boxer and closed within a threatening range. The ship took defensive action against the UAS to ensure the safety of the ship and its crew," Chief Pentagon spokesman Jonathan Hoffman wrote.

"We assess the UAS to be Iranian," Pentagon spokeswoman Cdr. Rebecca Rebarich told CNN.

Tensions in the Strait of Hormuz

A US military official told CNN that members of the 11th Marine Expeditionary Unit aboard the USS Boxer were operating counter-drone jamming equipment and downed the suspected Iranian aircraft.

US Marines from that unit are trained to use maneuverable, ground-based jamming systems "that can detect, identify and defeat drones with electronic attack," according to the Department of Defense . Those systems can be used while on land or aboard a ship like the USS Boxer.

The incident comes almost exactly one month after Iran shot down an American drone , further heightening the already volatile conditions in the Middle East.

Iran's Revolutionary Guard said at the time that it had shot down an "intruding American spy drone" after it entered into the country's territory. A US official confirmed to CNN a drone had been shot down, but said the incident occurred in international airspace over the Strait of Hormuz, one of the world's most vital shipping routes

There is no place in the world more important for the global supply of oil than the Strait of Hormuz and the US has vowed to never allow Iran to prevent open passage through the waterway.

The channel, which is only 21 miles wide at its narrowest point, is the only route to move oil from the Persian Gulf to the world's oceans.

Mixed messages

After last month's downing of a American drone, Trump said that he called off a retaliatory strike on Iran just as the US was "cocked & loaded" to strike because he decided there would be too many deaths for a proportionate response.

Since that time, Trump has attempted to paint a more optimistic view of the prospects for diplomacy with Iran.

On Tuesday, the US President said "a lot of progress" has been made with Tehran.

"They'd like to talk. And we'll see what happens but a lot of progress has been made," he said.

"We want to help them. We'll be good to them," Trump added. "We'll help them in any way we can. But they can't have a nuclear weapon."

And earlier Thursday, Trump said that "Iran is a much different country right now than when I took over," adding that, at the time he took office, the country was the "scourge of the world."

But CNN reported Wednesday that the Trump administration is also reinforcing its controversial military relationship with Saudi Arabia by preparing to send hundreds of troops to the country amid increasing tensions with Iran.

Five-hundred troops are expected to go to the Prince Sultan Air Base, located in a desert area east of the Saudi capital of Riyadh, according to US two defense officials. A small number of troops and support personnel are already on site with initial preparations being made for a Patriot missile defense battery as well as runway and airfield improvements, the officials said.

The US has wanted to base troops there for some time because security assessments have shown Iranian missiles would have a difficult time targeting the remote area.

Last month the administration announced it was sending 1,000 additional troops to the Middle East as issues with Iran flared but did not specify which countries they were going to. The forces going to Saudi Arabia are part of this deployment.