The U.S. Treasury Department hit Russia's VTB Bank with new sanctions, accusing the financial institution of attempting to move frozen Iranian assets through the global financial system to benefit Tehran.

"VTB Bank opened offices in Iran, built banking ties with sanctioned Iranian financial institutions, and worked to move billions of dollars in Iranian assets," Treasury Department spokesperson Tmmy Pigott said in a statement on Monday. "The United States remains steadfast in cutting off the financial lifelines that allow the Iranian regime to fund terrorism, destabilize the region, and threaten U.S. economic security."

VTB, a majority state-owned entity registered in Saint Petersburg, was first penalized by Treasury's Office of Foreign Assets Control following Russia's annexation of Crimea in 2014 and then designated by the US following Moscow's invasion of Ukraine in 2022, a step which cut it off from the SWIFT financial messaging system. Still, VTB -- Russia's second-largest financial institution -- reported record profits in 2024 and has continued to expand.

ABC News has learned that the Treasury Department officials assess that this round of sanctions could be more effective in encouraging foreign banks to cut ties with VTB than earlier Russia-related measures because the authorities they have been issued under are associated with Iran and global terrorism concerns, which have traditionally enjoyed broad UN support and greater levels of compliance.

The Treasury Department is also announcing that it will meet with global financial institutions this week in order to "arm them with the information they need to shut down revenue streams and procurement networks tied to the Iranian regime, the IRGC, Iran's terrorist proxies, and their enablers."

-ABC News' Shannon Kingston

President Donald Trump is continuing to deny recent accounts that U.S. munitions stockpiles are dwindling as the war in Iran carries on, saying in a social media post Monday that he "just received a Report that the United States is producing more Exquisite and Elite Weapons than at any time in our History."

He said the high-grade weapons are being delivered “daily” to military forces in the Middle East, specifically highlighting that production has been focused on Patriot missiles, THAAD anti-ballistic missile systems, Tomahawk missiles and other "Standard Missile Systems."

-ABC News' Isabella Murray

President Donald Trump is now saying that he is "open" to the "concept" of negotiating a deal with Iran.

"The failing Nation of Iran wants to make a deal, quickly and badly. I will determine whether or not the U.S.A. will choose to engage -- The concept of which we are open to,” Trump said on his social media platform on Monday.

This comes despite the president's recent comments casting doubt on Iran's trustworthiness and suggesting a deal wouldn't hold any value.

"I think an agreement with them isn't worth the paper it's written on," Trump told Fox News on Sept. 1. That day, he also posted: "I couldn't care less if they sign a worthless, to them, agreement."

On Sunday, Trump said he would only make a deal with Iran if it is the "right deal," but offered no other details about what this would look like.

-ABC News' Emily Chang

Iran "does not interfere in Yemeni affairs," Iranian Foreign Ministry spokesperson Esmaeil Baqaei said in his Monday press conference, saying Iran has "no relations whatsoever with what is unfolding in Yemen."

Iran has long maintained a military and political relationship with the Houthis, with its adversaries accusing Tehran of training, funding and arming the Yemeni group as part of its so-called "Axis of Resistance."

Analysts have attributed Iranian assistance for the growth in scale and sophistication of the Houthi ballistic missile and drone arsenals, in particular.

Last week saw the start of a new round of intense fighting on Yemen's western Red Sea coast, between the Houthis and forces loyal to the Saudi-backed internationally-recognized Yemeni government.

Fighting was continuing as of Monday, according to reports. Clashes were reportedly ongoing in the area on the mainland near Perim Island, which sits in the middle of the strategic Bab el-Mandeb Strait.

-ABC News' Victoria Beaule