"We will return to the US to re-impose sanctions so that the arms embargo will become permanent next week," Secretary of State Mike Pompeo said at a press briefing
The sanctions add to conflict over control of the sea, one of the world's busiest shipping lanes.
The sanctions had been eased under the 2015 nuclear deal that President Donald Trump withdrew from two years ago.
In the toughest US action on Hong Kong since China imposed a sweeping new security law on the territory, Washington on Friday sanctioned a group of Chinese and Hong Kong officials.
The economic meltdown presents a serious challenge for Assad, who survived more than nine years of war but rules over a crumbling infrastructure and ravaged economy.
Wilmots quit as head coach of Iran Team Melli, just seven months after replacing Carlos Queiroz at the helm of the three-time Asian champions.
Indian Oil Corp will lift 6 million barrels of Iranian oil and Mangalore Refinery and Petrochemicals Ltd 3 million barrels, the source told Reuters.
The deal has been an issue of much speculation after US President Donald Trump's administration's law -- Countering America's Adversaries Through Sanctions Act (CAATSA) -- came into effect in January.
Traders said global oil markets remained tense because of the looming U.S. sanctions against Iran's oil exports, which kick in from Nov. 4.
Though India, one of the biggest importers of Iranian oil, has already reduced its import, it has indicated that it is unlikely to go down to zero given its massive energy needs.
The United States from Nov. 4 will target Iran's oil exports with sanctions, and Washington is putting pressure on governments and companies around the world to fall in line and cut their purchases.
So far, the 28-nation bloc has not put forward a concrete proposal for making payments to Iran for buying of oil.
US President Donald Trump reimposes tough, unilateral sanctions against Iran after exiting 'horrible' nuclear deal
Iranians are already seeing the effects of the sanctions, with Iran's rial currency losing around half its value since Trump announced the US would withdraw from the 2015 nuclear accord.
We will not let the current attack, or any new anti-Russian attack, go without a tough response, Russia's foreign ministry said in a statement.
Trump's administration targeted seven oligarchs, 12 companies they own or control, 17 senior Russian officials and a state-owned arms export company.