The Biden administration on Wednesday unveiled new sanctions targeting Iran's ballistic missile and drone programs as the United States and dozens of other partners vowed to continue to counter those programs as a set of United Nations restrictions expired.

The US Treasury Department said in a news release that it was imposing the sanctions on "11 individuals, eight entities, and one vessel based in Iran, Hong Kong, the People's Republic of China (PRC), and Venezuela that are enabling Iran's destabilizing ballistic missile and unmanned aerial vehicle (UAV) programs."

In a separate move, the US State Department imposed sanctions on two Iranian officials "for engaging in activities that have materially contributed to Iran's missile program," as well as on "two Iran-based entities and four Russia-based entities." Russia has been using Iranian drones in its war in Ukraine.

The announcement of the new sanctions comes on what is known as "Transition Day," when the remaining UN restrictions on Tehran's ballistic missile program from the 2015 Iran nuclear deal lapse. It also comes as tensions in the region have escalated dramatically following Hamas' deadly attacks on Israel and as Tehran threatens to join the war.

Iran has increasingly violated the terms of nuclear agreement in the eight years since its adoption, particularly after the US withdrew from the deal under the presidency of Donald Trump. Efforts in recent years to restore the deal have collapsed and Tehran has increasingly grown its nuclear program in violation of the limits of the deal.

In light of this, countries like Germany, France, and the United Kingdom -- known as the E3 -- and the US have said they will maintain similar constraints on Iran's missile program through their own national sanctions, despite the expiration of the UN restrictions.

A senior State Department official said Wednesday "we're very concerned about Iran's proliferation of missiles and UAVs," and as such have sought to send "a resounding signal" to Tehran that "we're not going to stand by."

The US and 45 other countries that signed on to the joint statement Wednesday committed to "take all necessary measures to prevent the supply, sale, or transfer of ballistic missile-related items, materials, equipment, goods, and technology, to protect peace and stability in the region and beyond."

In addition to the new sanctions and the joint statement, the Biden administration on Wednesday also issued a notice to private industry about Iran's ballistic missile program, noting that "private industry is on the front line of detecting and denying Iran's procurement efforts."

Under the nuclear deal, parties to the agreement can move to "snap back" the restrictions on Iran -- a move attempted and failed under the Trump administration.

Kelsey Davenport, the diirector for Nonproliferation Policy at the Arms Control Association, told CNN "the states that would be deterred from doing business with Iran because of UN sanctions would be deterred by European and US sanctions.

"It's unfortunate that these measures are going to expire, but snapping them back wouldn't have any practical effect and Iran would retaliate, setting off another escalatory spiral," she said, noting that "Iran has made very clear that it will consider withdrawing from the Nuclear Nonproliferation Treaty if the sanctions are snapped back."

"The calculation appears to suggest that the risks of reimposing UN sanctions outweigh the benefits," she explained. "If UN sanctions were going to stop Iran's illicit missile and drone trade, I think the calculation would be different, but it's clear that the UN sanctions are not effective in halting that trade. So I think it would be a significant escalation, without much tangible benefits."

Iranian officials have criticized the decision by Western countries to maintain sanctions on Tehran despite the expiration of the UN restrictions as "illegal."