RENEE MONTAGNE, HOST:
Nerves are fraying amid the ongoing tensions between the Trump administration and Iran. And concerns were heightened today when a U.K.-flagged supertanker came to a stop in the Persian Gulf. Iranian vessels were in the vicinity. It turns out the ship had simply put its voyage on pause so it could reach its next port of call on time. That's according to a British maritime organization. Joining us from Vienna is NPR's Peter Kenyon. He's been covering the situation between the U.S. and Iran. And, Peter, first, what actually did happen with this oil supertanker?
PETER KENYON, BYLINE: It was called the Pacific Voyager. It was traveling in the Persian Gulf, and then, suddenly, it stopped. Not long after that, the alarm bells started ringing on social media with people questioning, what is the supertanker doing? Why isn't it going on to its port? Asserting there were Iranian vessels in the area, what's going on? The speculation continued until eventually a group called U.K. Maritime Trade Operations weighed in. It's their job to coordinate commercial shipping in the Gulf. And an official with that group said they'd been in contact with the Pacific Voyager. It had simply paused in its travels to make sure that it got to its next destination on time, not early.
But in the meantime, Iran had been forced to respond. It angrily denied what it called these fabrications about something being amiss with the Pacific Voyager. So whether you want to call it a fabrication or just a misunderstanding of normal shipping practices, it appears this is not the next escalation in U.S.-Iran tensions as some may have feared.
MONTAGNE: Well, I'm going to presume that this kind of routine pause does not normally cause such a stir. Remind us why it might have today.
KENYON: Well, there's a list of reasons the U.S. has sent an aircraft carrier and strike group to the region, along with thousands of troops. Clearly, tensions are running high. We've had defiant comments from Iranian leaders, attacks on a half dozen tankers in recent weeks that the U.S. is blaming on Iran. Tehran denies any involvement. And to give a bit of context to this latest issue, on Friday, a former Revolutionary Guards commander was quoted as saying Iran should seize a British tanker in retaliation for the recent seizure of an Iranian tanker by the British Royal Marines. That happened in Gibraltar. That ship was carrying crude oil to Syria, something Iran's been doing for years now without incident, although it does violate EU sanctions. And then there was a direct attack on U.S. property. It was an Iranian attack on a U.S. drone shot down near the Strait of Hormuz. Iran did claim that act, saying it had entered Iranian airspace. The U.S. military denies that.
MONTAGNE: And, Peter, meanwhile, a top aide to Iran's supreme leader is sounding defiant about the country's nuclear program in the face of all this American pressure. Tell us about that.
KENYON: Yeah. This is an ongoing problem that is likely to continue. Senior aide Ali Akbar Velayati, he's now quoted as saying Iran is ready to begin enriching uranium above the current level. That happens to be 3.76%. Other officials have said tomorrow, Sunday, is the deadline for that increased enrichment to start. Now, this would be Tehran's second violation of the 2015 nuclear agreement. It has already exceeded the deal's cap on the amount of low-enriched uranium it can have. Iran's currently nowhere near weapons grade fuel. That would be 90% enriched. But if it gets over, say, 20%, that could trigger alarms and possibly response from the U.S.
For the moment, just the combination of having more fuel than the deal allows, plus possibly enriching it to a higher level, that is raising anxieties. And Washington has called a special meeting of the International Atomic Energy Agency. That's going to be held here in Vienna on Wednesday. And the topic will be Iran's nuclear program.
MONTAGNE: NPR's Peter Kenyon in Vienna, thanks very much.
KENYON: Thanks, Renee. Transcript provided by NPR, Copyright NPR.