The contingent was organized by Washington following attacks in June on oil tankers in the Strait of Hormuz that it blames on Iran. Britain, Australia, Saudi Arabia and Bahrain have also joined.
It's the largest one-day surge in crude prices in years. Yemen's Iranian-backed Houthi rebels claimed responsibility for the strikes, but the U.S. says Iran played a key role. Iran denies involvement.
The Iranian president's remarks on Tuesday were in contrast to an initially favorable reception to the idea. But he rejects the idea of a caucus that would essentially be just a photo-op.
The vessel, which was intercepted by British Royal Marines on July 4, left Gibraltar after a court there ruled that it had no authority to enforce U.S. sanctions against Iran.
The unidentified vessel was reportedly taken last Wednesday near Farsi island, where Iran maintains a naval base. Iraq's oil ministry has denied it has any connection with the ship.
The Iranian president called the Trump administration's move to sanction Foreign Minister Mohammad Javad Zarif "childish." Zarif tweeted that the sanctions would have "no effect" on him.
Iran shot down a U.S. drone. The U.S. launched a cyberattack and put new sanctions on Iran. Here is a look at the deepening crisis from Iran's standpoint.
Iran's shoot-down of a U.S. drone underscores the growing risk of conflict between the countries. If war occurs, President Trump will wish he stayed out, write Aaron David Miller and Richard Sokolsky.
A spokesman for the Atomic Energy Organization of Iran also says that Tehran is prepared to increase enrichment of uranium beyond what's permitted in the multilateral agreement.
Pointing to a U.S. military video, Trump maintained: "Iran did do it." Meanwhile, the president of the Japanese company operating one of the tankers says he doesn't believe a mine or torpedo was used.
The Japanese prime minister has offered to try to calm nerves between Washington and Tehran amid rising tensions that have followed the U.S. withdrawal from the 2015 nuclear deal.
Lately, the White House has been talking as if conflict with Iran could soon erupt. Here's a look at how the talk has turned so bellicose and what the risks are.
Right now, the best we can hope for is that the administration manages to muddle through and avoid a dangerous and unnecessary war, write former senior State Department officials.
