Secretary of State Mike Pompeo vowed Sunday that the US will guarantee free passage through the vital Strait of Hormuz, as he accused Iran of recent attacks on oil tankers and the downing of an American drone.

Pompeo confirmed in an interview with CBS that a US MQ-9 “Reaper” drone was shot down June 6 with a missile fired from Yemen “that we assess had Iranian assistance.”

Pompeo would not be drawn on what options the US is considering to protect shipping – or to punish Iran – in the wake of Thursday’s attacks on two tankers in the Gulf of Oman but reiterated that President Donald Trump is not seeking war with the Islamic republic.

“What you should assume is we are going to guarantee freedom of navigation throughout the strait,” he said in an interview on Fox News Sunday.

Iran has dismissed the US charges as “baseless” and said they were made without “a shred of factual or circumstantial evidence.”

A third of the world’s seaborne oil supply passes through the Strait of Hormuz, a narrow channel bordered to the north by Iran that links the Persian Gulf with the Gulf of Oman.

“This is an international challenge, important to the entire globe. The United States is going to make sure that we take all the actions necessary, diplomatic and otherwise, that achieve that outcome,” Pompeo said.

Rising tensions

The rising tensions have raised fears of an outbreak of hostilities in the tinderbox region.

“We don’t want a war. We’ve done what we can to deter this,” Pompeo said. “The Iranians should understand very clearly that we will continue to take actions that deter Iran from engaging in this … kind of behavior.”

The secretary would not lay out US evidence for Iran’s involvement in the Gulf of Oman explosions, but insisted: “It’s unmistakable what happened here.

“These were attacks by the Islamic Republic of Iran on commercial shipping, on the freedom of navigation, with the clear intent to deny transit through the strait.”

The Pentagon had previously released a video showing what it said was an Iranian boat that pulled up alongside one of the stricken tankers and removed a limpet mine attached to its hull.

Some allies, skeptical of US intentions, have said they wanted to see more evidence before reaching a conclusion.

“I will concede that there are countries that wish this would just go away,” Pompeo said.

He expressed confidence that “as we continue to develop the fact pattern, countries around the world will not only accept the basic facts, which I think are indisputable, but will come to understand that this is an important mission for the world.”

Adam Schiff, head of the House Intelligence Committee and a leading Democratic critic of the administration, said the evidence of Iranian involvement “is very strong and compelling.”

He told CBS’s Face the Nation: “I think this was a Class-A screw-up by Iran to insert a mine on the ship.

“It didn’t detonate, they had to go back and retrieve it. I can imagine there are some Iranian heads rolling from that botched operation.”

The administration’s struggle to persuade its allies, however, “shows just how isolated the United States has become,” he added.

Meanwhile, the Kremlin on Sunday warned against “baseless accusations” over last week’s attacks.

“Such incidents can undermine the foundations of the world economy. That’s why it’s hardly possible to accept baseless accusations in this situation,” said Kremlin spokesman Dmitri Peskov.

“We always urge a sober appraisal of the situation and to wait for more or less convincing evidence to appear,” Peskov said on Russian television, extracts of which were published by the RIA Novosti news agency.

The official Iranian news agency IRNA said the attacks took place within 30 nautical miles of Iran’s coastline.

Iran rejected US accusations it was to blame, with Foreign Minister Mohammad Javad Zarif tweeting that the US had “immediately jumped to make allegations against Iran without a shred of factual or circumstantial evidence”.

Saudi Arabia, Iran’s arch-rival in the region and the world’s top oil exporter, joined Washington in accusing Tehran of the attacks, with Saudi Crown Prince Mohammed bin Salman saying he “won’t hesitate” to tackle any threats to the kingdom.

For his part the speaker of the Iranian parliament, Ali Larijani, hinted Sunday that Washington could be behind the “suspicious” tanker attacks in order to pile pressure on Tehran, IRNA reported.

Moscow “severely” condemned the attacks, he said, warning against drawing “hasty conclusions.”

– reporting by AFP