Iran just heated up tensions with Trump in a major show of force to practice closing the Strait of Hormuz

Reuters

A military personnel participates in the Velayat-90 war game on Sea of Oman near the Strait of Hormuz in southern Iran December 28, 2011

• Iran is about to launch a major military exercise in the Persian Gulf to show they can close the Strait of Hormuz.
• Iran has been threatening to close the Strait of Hormuz in response to President Donald Trump's threats to sanction countries that import Iranian oil.
• While the impending large Iranian military exercise has US officials concerned, experts believe Tehran is most likely bluffing that they would ever do this.

Iran is about to launch a major military exercise in the Persian Gulf to show they can close the Strait of Hormuz, according to CNN, citing two US officials.

"We are aware of the increase in Iranian naval operations within the Arabian Gulf, Strait of Hormuz and Gulf of Oman," Captain William Urban, a spokesman for CENTCOM, said in a press statement. "We are monitoring it closely, and will continue to work with our partners to ensure freedom of navigation and free flow of commerce in international waterways."

"We also continue to advocate for all maritime forces to conform to international maritime customs, standards and laws," Urban added.

The Strait of Hormuz is a sea passage into the Persian Gulf between Iran and Oman, through which about 30% of the world's oil supply passes.

Lisi Niesner/Reuters

Iran is rejecting President Donald Trump's offer to hold talks.

President Donald Trump has lately been in a war of words with the leaders of Iran.

In June, Trump threatened sanctions on countries that purchase oil from Iran, to which Tehran responded by threatening to shut down the Strait of Hormuz.

Trump, Rouhani and even a powerful Iranian general, Maj. Gen. Qassem Soleimani, have also been bickering back and forth over the last couple weeks with alarming rhetoric.

CNN reported that US officials see this anticipated Iranian military exercise as alarming for three reasons: it comes as rhetoric between the two nations heats up, it will be a larger exercise than previous ones and Tehran usually holds such exercises later in the year.

The US also believes that the Iranian military exercise will include about 100 naval vessels, most of which are small boats, as well as air and ground forces, CNN reported.

Iran has repeatedly used small, fast-attack craft to harass US Navy warships over the last several years.

Fars News Agency Photo via USNI News

Iran's fast attack craft, the type repeatedly used to harass US Navy ships.

Nevertheless, these Iranian threats are most likely a bluff.

"In the event Iran choose to militarily close the Strait of Hormuz, the U.S. and our Arabian Gulf allies would be able to open it in a matter of days," retired Adm. James Stavridis previously told CNBC.

And Iran most likely knows this, which spark questions about Iran's intentions.

Tehran is bluffing about closing the Strait of Hormuz because "just the threat of doing that [will send] oil prices up," Former US Ambassador to Turkey James Jeffrey, now an expert at the Washington Institute, previously told Business Insider.

"They're doing this to spook consumers," of Iranian oil, said Jeffrey.