Iran said on Wednesday it rejected a US offer of aid for survivors of twin deadly earthquakes that struck villages in its northwest on the weekend because it was not made in "good faith."

"Iran did not accept the US offer for sending humanitarian aid for quake survivors," Hassan Ghadami, the head of the interior ministry's crisis management organisation, said, according to the ISNA news agency.

"We do not believe the US put forward the offer in good faith. We are currently having a medicine supply crisis because of sanctions," Ghadami said.

"Do us a favour and lift the sanctions," he said, referring to Washington's campaign of draconian economic sanctions imposed on Iran.

A day after twin earthquakes struck Iran last Saturday, killing 306 people and injuring 3,000 according to an official toll, the United States issued a statement sending "the Iranian people" its condolences and saying: "We stand ready to offer assistance in this difficult time."

Iran's response underlined what it saw as US hypocrisy, given that Washington this year has done all it can to isolate Tehran.

Although Iran's Red Crescent said it had rejected other offers of aid from Germany, Taiwan and Russia, media reports say humanitarian cargoes from a handful of countries -- Qatar, Pakistan, Switzerland and Azerbaijan -- have arrived.

The United States stressed that Americans had ways of sending assistance to Iran for the quake, despite the sanctions.

"Americans wishing to provide humanitarian assistance to Iranians during this time may donate food and medicine without obtaining an Iranian transactions regulations licence," State Department spokeswoman Victoria Nuland said Monday.

"Certain non-commercial personal financial transactions" to Iran also remained legal, she said.

The National Iranian American Council, an advocacy group for the US-based community, has called on the US government to ensure that quake relief efforts "are not obstructed due to the dispute between the US and Iranian governments."

The twin quakes on Saturday, measuring 6.4 and 6.3 on the moment magnitude scale, flattened hundreds of hamlets in Iran's mountainous northwest, near the city of Tabriz.

The United States and Iran have no diplomatic relations and have been involved in a tense diplomatic standoff for decades, most recently over Tehran's nuclear programme.

The US sanctions, and others imposed by the European Union, aim to pressure Tehran to roll back its nuclear activities, which the West fears are geared to developing atomic weapons. Iran denies its programme is anything but peaceful.