Tehran’s enemies dare not “fire even a single bullet” at Iran, a deputy commander of the Islamic Revolutionary Guard Corps (IRGC), a U.S.-designated terrorist organization, declared in a defiant tone while highlighting the Shiite country’s allegedly strong deterrence capabilities on Thursday.

“No one dares to fire even a single bullet at our country, and without exception, the enemy has faced defeat [in its anti-Iran moves],” Rear. Adm. Ali Fadavi, the IRGC deputy commander for coordination, declared during a military ceremony in Iran on Thursday, the state-run Tasnim News Agency reports.

Iran considers the United States, Israel, and Saudi Arabia to be its top enemies. Nevertheless, three IRGC gunboats attempted to seize a British oil tanker in the Strait of Hormuz overnight on Wednesday, but the Royal Navy stopped them. The Strait of Hormuz is considered one of the most strategically important, crowded, and contested waterways on the planet.

Citing unnamed military sources, with “direct knowledge of the incident,” CNN reports that the British frigate “trained its deck guns on the Iranians and gave them a verbal warning to back away,” forcing the Iranians to withdraw.

The U.K. Ministry of Defense declared in a statement on Thursday:

Contrary to international law, three Iranian vessels attempted to impede the passage of a commercial vessel, British Heritage, through the Strait of Hormuz. [British frigate] HMS Montrose was forced to position herself between the Iranian vessels and British Heritage and issue verbal warnings to the Iranian vessels, which then turned away. We are concerned by this action and continue to urge the Iranian authorities to de-escalate the situation in the region.

Iran has reportedly denied responsibility for the incident.

Adm. Fadavi’s comments also came against a backdrop of heightened tensions between the United States and Iran, largely fueled by Tehran’s decision to shoot down an American drone last month and U.S. President Donald Trump’s historic wave of sanctions that have crippled the Iranian economy.

The United States has denied Iran’s claims that the downed drone violated the Islamic Republic’s territorial waters and airspace.

In recent weeks, the IRGC has been boasting about its power and deterrence capabilities, saying on Tuesday that the downing of the American drone “shattered” U.S. military awe.

Maj. Gen. Hossein Salami, the IRGC’s commander-in-chief, reportedly credited Iran’s military might last week with prompting Trump’s last-minute reversal on a June 21 attack on the Islamic Republic in response to the drone incident, over concerns that the assault would kill dozens of civilians.

Last month, Tehran demanded that the United States pull American troops out of the Persian Gulf region, threatening a strong response if the U.S. violates its borders.

Adm. Fadavi claimed on Thursday that Tehran’s “enemies are fully aware that the power of the Islamic Republic of Iran has remarkably increased,” according to Tasnim.

However, Brian Hook, the U.S. special representative for Iran, told American lawmakers last month that the Trump sanctions have significantly reduced Tehran’s military spending, hindering the Shiite country’s ability to enhance the capabilities of its armed forces.

Speaking to news outlets in the Middle East, Hook also noted last month that the Trump administration’s sanctions are “on track” to deny Iran “$50 billion” in oil revenues alone.

Hook acknowledged to U.S. lawmakers that “Iran still, even with very little revenue, has asymmetric capabilities that terrorists have.”

The Trump administration considers Iran to be the world’s leading state-sponsor of terrorism.

President Trump’s “unprecedented” maximum pressure campaign against Iran is “working,” Hook told lawmakers, noting that the sanctions have hindered Tehran’s abilities to continue funding its proxies, namely anti-America Shiite militias in Iraq and the Lebanese narco-terrorist group Hezbollah, which operates in the Western Hemisphere.