Iran live updates: Tehran plans new 'restricted zone' outside Strait of Hormuz

Mohammad Bagher Ghalibaf, Iran's chief negotiator and the speaker of the country's parliament, said in a speech posted to Telegram on Sunday that "the era of 'proportionate responses' is over."

The recent Iranian strikes targeting U.S. bases in the Middle East were "only the beginning," Ghalibaf said.

"The rules of the game have changed, and from now on, any transgression against the interests and security of Iran will receive a 'faster, heavier, and more painful' response," Ghalibaf said.

-ABC News' Rashid Haddou

Iran's IRGC navy said in a statement on Saturday that they have targeted three oil tankers which have been sailing through "an unauthorized route" in the Strait of Hormuz, as well as three vessels affiliated with the United States in other areas.

The IRGC navy warned all vessels in the Persian Gulf and near the Strait of Hormuz "not to be deceived" by the U.S. military and refrain from "any suspicious movement" to pass through unauthorized waterways or they would be targeted.

The U.S. has not immediately commented about the claims.

-ABC News' Somayeh Malekian