DUBAI — Iran's supreme leader, Ayatollah Mojtaba Khamenei, vowed in a written statement read by a state television anchor that the Islamic Republic would protect its nuclear and missile capabilities as a national asset. Khamenei also said that the only place Americans belong in the Persian Gulf is at the bottom of its waters.

"Ninety million proud and honorable Iranians inside and outside the country regard all of Iran's identity-based, spiritual, human, scientific, industrial and technological capacities — from nanotechnology and biotechnology to nuclear and missile capabilities — as national assets, and will protect them just as they protect the country's waters, land and airspace," Khamenei said. He added that a new chapter was being written in the region's history.

Addressing Iran's position over the waterway at the mouth of the Persian Gulf, Khamenei said: "Islamic Iran, by giving practical thanks for the blessing of exercising control over the Strait of Hormuz, will make the Persian Gulf region secure and put an end to the hostile enemy's abuses of this waterway." He referred to America as the Great Satan, a term Iranian leaders have used since the 1979 Islamic Revolution. Since taking over as supreme leader, Khamenei has spoken through written statements read by a state television anchor.

The statement came as the United States and Iran remained locked in a standoff over the Strait of Hormuz, the narrow mouth of the Persian Gulf through which a fifth of all crude oil and natural gas traded passes. The strait lies in the territorial waters of Iran and Oman, and Iran maintains control over it. Iran had been charging some ships approximately $2 million each to transit the waterway.

A U.S. Navy blockade has halted Iranian oil tankers from getting out to sea, squeezing Iran's oil industry. The blockade is designed to prevent Iran from selling its oil and deprive it of revenue, and could force Iran to shut off oil production because it has nowhere to store the oil. The measure has also pressured U.S. Gulf allies that use the waterway to export oil and gas.

A recent Iranian proposal would delay negotiations on the country's nuclear program. Iran has enriched uranium to near-weapons-grade levels of 60%. President Donald Trump said one of the major reasons he went to war was to deny Iran the ability to develop nuclear weapons.