The restrictions are the latest in Washington's two year+ effort to ratchet up pressure against Tehran following President Trump's May 2018 decision to exit the Iran nuclear deal.

The Treasury Department introduced a fresh round of Iran-related sanctions on Wednesday, targeting the country's prison system, as well as Interior Minister Abdolreza Rahmani Fazli.

The new sanctions affect the Great Tehran Penitentiary in Iran's capital, the Law Enforcement Forces Cooperative Foundation, and Qarchak Prison, also situated in Tehran. All three entities are targeted with secondary Countering America's Adversaries Through Sanctions Act (CAATSA)-related restrictions.

Fazli was one of nine Iranian officials added to the Treasury's Iran sanctions list, which also target chief of police Hossein Ashtari, deputy police chief Ayoub Soleimani and police general Mohsen Fathizadeh.

The new restrictions come less than 24 hours after the sanctioning of a Chinese logistics company providing services to Iran's Mahan Air, and weeks after the May 1 sanctioning on an Iran-related mining company in Oman, and an individual said to be linked to Iran's Revolutionary Guards.

The Iran-related sanctions are part of a broader campaign of US sanctions against a host of nations US doesn't like or has issues with, including Venezuela, Syria, Russia and China, although Tehran has been the Treasury's main target during the Trump administration.

Iranian officials have slammed Washington over the restrictions amid the COVID-19 pandemic, saying sanctions prevent the country from selling its oil and importing much-needed supplies and medical equipment to deal with the virus. At the same time, Iran's scientists and industry have worked to ramp up production of homegrown medical equipment, disinfectants and testing kits to deal with the medical crisis.

The sanctions come amid historically chilly relations between Washington and Tehran, with tensions soaring in May 2018 when Washington unilaterally pulled out of the Iran nuclear deal, and flaring in a string of tanker seizures, drone shootdowns, assassinations and missile strikes in the two years since. On Tuesday, the Pentagon warned Iranian gunboats to stay "at least 100 meters from US vessels" in international waters or "be interpreted as a threat," with the notice coming a week after the US Navy complained that its warships were being "harassed" while sailing near Iran's shores earlier this month.

Iranian Media Refute Israel's Claim That Tehran is Scaling Down Its Presence in Syria

Previously, outgoing Israeli Defense Minister Naftali Bennet commented that Iran "has begun the withdrawal process from Syria," his uncorroborated-by-evidence statement coming in the wake of earlier reports of Israeli officials suggesting there was a scaling down of Tehran’s presence in the country.

An Iranian military source has been cited by Fars News Agency as refuting earlier statements made by outgoing Israeli Defense Minister, Naftali Bennett, that Tehran was reducing its presence in Syria.

"There has been no change in the quantity and quality of Iran's advisory presence in Syria… We will stay in Syria as long as the Syrian government needs the help of the Iranian advisers," the well-informed military source was quoted as saying.

While emphasizing that Naftali Bennett’s allegations are “an attempt to fill his empty record of any achievement,” the source underscored that Iran’s presence in Syria was the result of an official request of the legitimate Syrian government, seeking help in combating terrorism in this country.

The source was also cited by Tasnim News Agency as adding that the outgoing Israeli Defense Minister’s statements “are similar to the continuing allegations of the Zionist entity regarding the implementation of successful military operations against Iranian forces in Syria or cyberattacks on various installations in Iran, which are far from reality.”

Earlier, Special Assistant to the President of the Iranian Parliament for International Affairs, Hussein Amir Abdullahian, said in an interview with Al-Alam TV on Sunday that there was “no justification for the Islamic Republic to reduce the number of its forces in Syria”, stressing that “the Americans wanted to remove Syrian President Bashar al-Assad and topple the political system in Syria, but they failed, and today they send messages to President Assad and offer him agreements.”

Hussein Amir Abdullahian concluded by emphasizing that “the Iranian advisory presence will continue in Syria as long as the Syrian government requests that from Tehran”.

The response from the Iranian side followed a statement by outgoing Israeli Defense Minister Naftali Bennett on Monday that Iran had started withdrawing its forces from Syria.

While not offering any evidence to corroborate his assertions, in his farewell speech, quoted by Reuters, Bennett said:

“Iran is significantly reducing the scope of its forces in Syria and even evacuating a number of bases… Though Iran has begun the withdrawal process from Syria, we need to complete the work. It’s in reach.”

 Warning that unless pressure on Tehran is preserved the trend might reverse, Naftali Bennett called upon his successor, Benny Gantz, to continue to toe the line.

Earlier in the month, US officials also weighed in on reports of a downscaling of Iranian presence in Syria.

Special Representative on Syria James Jeffrey was cited by Newsweek as telling reporters Washington saw "some Iranian movement around Syria pulling back from areas where the Israelis have struck them" as well as "a withdrawal of Iranian-backed militias" from other countries.

There has not yet been any official response from Tehran or Syria to Bennett’s comments.

Iran, which is struggling under US economic sanctions, has repeatedly insisted its military presence in Syria is at the invitation of Bashar Assad’s government, vowing to remain in the country as long as its help is needed.