The United States has said it will temporarily lift sanctions for U.S.-based non-governmental organizations that want to send financial aid to help Iran's earthquake relief effort, BBC News reported.

Until now U.S. sanctions allowed food and medicines to be sent to Iran for humanitarian reasons, but not money.

Iran initially declined outside aid after two strong quakes hit its northwest, killing at least 300 people.

Tehran has been criticized for responding slowly to the disaster.

The U.S. Department of Treasury order comes after several US-Iranian non-governmental organizations (NGOs) pressed the White House to lift restrictions on sending money so that they could support charities on the ground.

The U.S. has imposed heavy sanctions on Iran because of its nuclear program, which Washington suspects is aimed at building a nuclear weapon.

Tehran has always denied these accusations, insisting that it is developing nuclear technology for civilian purposes such as energy production.

Current U.S. sanctions on Iran are meant to target Iranian officials and institutions, particularly those that Washington regards as directly involved in Iran's nuclear program.