Russia has dismissed "illegitimate" sanctions imposed by the United States on the Central Bank of Iran (CBI), vowing to continue its cooperation with the Islamic Republic in the banking sector.

The US Department of the Treasury announced in a press release on Friday that its Office of Foreign Assets Control (OFAC) had taken action against the CBI, the National Development Fund of Iran (NDF), and Etemad Tejarate Pars Co. under its counterterrorism authority.

It claimed that the CBI had provided billions of dollars to the Islamic Revolutionary Guards Corps (IRGC), its Quds Force and the Lebanese resistance movement Hezbollah.

Addressing reporters at the White House on Friday, US President Donald Trump said the new sanctions represent the "highest sanctions ever imposed on a foreign country."

After the announcement of the new sanctions, a Russian Foreign Ministry official said Moscow would not be affected by Washington's new punitive measures against Tehran.

"This will not affect our approaches to Iran. As we planned, we will continue to cooperate with Iran in the banking sector. This will have no effect [on Russia's position]," said Zamir Kabulov, the director of the Russian Foreign Ministry Second Asian Department.

The Trump administration has vowed a response after US officials blamed Iran for an attack against two Saudi oil facilities over the weekend.

On September 14, Yemen's Houthi Ansarullah fighters conducted strikes on two of Saudi Arabia's oil facilities in Abqaiq and Khurais. The attacks led to a halt in about 50 percent of the kingdom's crude and gas production, causing a surge in oil prices.

The Houthi movement officially took credit for the attacks, but US Secretary of State Mike Pompeo swiftly blamed Iran. Furthermore, President Trump said a short while later that the US was “locked and loaded” for a response at the behest of Riyadh, although he later said he wanted no conflict with any country.

Still later, the Pentagon reportedly prepared "response" options for the American president.

Tensions have significantly risen as a result of the accusations leveled against Iran, which Tehran has rejected, calling them an attempt by the White House to shift from a failed campaign of "maximum pressure" to one of "maximum lying" and "deceit" against the Islamic Republic.

Iranian Foreign Minister Mohammad Javad Zarif said in a Friday posting on Twitter that US-allied Saudi Arabia and the United Arab Emirates apparently want to "fight Iran to the last American."

In his tweet, the top Iranian diplomat dismissed his American counterpart's claims and said, "@SecPompeo has it the other way around: It's not #Iran that wishes to fight to the last American; rather, it is his #B_Team hosts who seem to wish to fight Iran to the last American."