Iran has rejected a United States offer of aid for survivors of deadly earthquakes which struck villages in its north-west, saying the offer was not made in "good faith".

The weekend earthquakes killed 306 people and injured 3,000, according to an official toll, and the US issued a statement sending "the Iranian people" its condolences and saying, "we stand ready to offer assistance in this difficult time".

However, the head of the interior ministry's crisis management organisation, Hassan Ghadami, told local media Iran had declined aid offers.

"Iran did not accept the US offer for sending humanitarian aid for quake survivors," he said.

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

"Do us a favour and lift the sanctions."

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

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, including Qatar, Pakistan, Switzerland and Azerbaijan, have arrived.

The US 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.

"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 US and Iran have no diplomatic relations and have been involved in a tense diplomatic standoff for decades, most recently over Tehran's nuclear program.

AFP