"After earthquakes in 2003 and 2012, the United States demonstrated its compassion and goodwill by offering assistance to the Iranian people and allowing private relief donations," the senators wrote, according to Common Dreams.

"This time should be no different."

While the rescue and relief teams are still working in the quake-hit areas after three cold nights, the latest figures show that over 450 people have died and 9,388 others wounded in the quake as of Saturday morning.

The Sunday night’s earthquake measuring 7.3 on the Richter scale, whose epicenter was near Iraq’s Sulaymaniyah, was the deadliest of the year, eclipsing the one that hit Mexico City in September, and was felt as far away as Turkey and Pakistan.

Under the current sanctions regime, Iranian-Americans living in the US are prohibited from delivering funds to their friends and family members.

Media reports say several attempts by Iranian-Americans to set up fundraisers for Iran in the days following the earthquake have been stymied by US Treasury Department rules.

"The way it is now, it is extremely difficult," Tara Kangarlou, a New York-based Iranian-American journalist, said of the economic restrictions.

"These are the moments that you realize how political tug of war are hurting ordinary Iranians."

As for official US government assistance, the Trump White House has been relatively quiet; the Treasury Department called the quake "tragic" in a statement, but did not say whether the administration plans to mount any kind of response. Trump, himself, has not said a word about the quake, which Sanders and his Democratic colleagues noted was "the world's deadliest of the year."

In addition to killing hundreds and injuring over 9,000, a report from European Civil Protection and Humanitarian Aid Operations found that the tremor damaged 12,000 buildings in Iran and Iraq.

Shortly after the earthquake struck, Sanders highlighted the "growing tensions" between the US and Iran—particularly following Trump's decision to decertify the Iran deal—and argued that providing relief to the Iranian people following such a devastating event "would be an important act of friendship."

Read the senators' full letter:

We write today concerning the recent earthquake that struck Iran on November 12. The latest reports indicate over 500 dead and thousands wounded, making this earthquake the world's deadliest of the year. We urge you temporarily waive any existing restrictions that would impede relief donations in order to speed the delivery of aid.

While the earthquake affected both Iran and Iraq, most of the casualties are on the Iranian side of the border. After earthquakes in 2003 and 2012, the United States demonstrated its compassion and goodwill by offering assistance to the Iranian people and allowing private relief donations. The administrations of George W. Bush and Barack Obama both temporarily waived sanctions, and the Department of the Treasury's Office of Foreign Assets Control (OFAC) issued general licenses to simplify aid delivery.

Under the Bush administration, an OFAC license authorized US persons to provide cash donations to nongovernmental organizations, US and non-US, assisting with relief efforts in Iran. At the time, OFAC also worked with aid organizations to clarify rules on donations of food and medicine and which Iranian entities could receive aid and eased banking constraints to ensure the timely receipt of donations in Iran. While we understand that a general license issued by OFAC in 2013 allows for US nongovernment organization to deliver aid to Iran, we urge you make it easier for US citizens to contribute to nongovernment organizations not based in the United States that are currently providing relief aid to earthquake victims in Iran.

Despite decades of animosity and no formal diplomatic relations, the United States has routinely offered to help the Iranian people in times of need. This time should be no different. We ask that you direct the Department of State to assist in aid efforts and to coordinate such efforts with OFAC and other relevant agencies in order to ensure aid arrives quickly.

Thank you for your attention to this matter. We look forward to your timely response.