UNITED NATIONS - The United Nations stands ready to assist efforts to respond to a deadly earthquake that struck Iran and Iraq on Sunday, UN Secretary-General Antonio Guterres said.

The UN chief "is deeply saddened by the loss of life and damage" after the 7.3-magnitude earthquake struck the border regions of the two countries, said a statement issued by his spokesman Stephane Dujarric on Monday.

More than 400 people were killed and about 7,000 others injured after the powerful earthquake hit the Iran-Iraq border area, local media reported on Monday.

The statement said the secretary-general conveyed his condolences to the bereaved families and to the governments and people of Iran and Iraq, and wished those injured a speedy recovery.

He also commended the local response efforts underway.

"The United Nations stands ready to assist if required," read the statement.

The earthquake is the deadliest of the year, eclipsing the one that hit Mexico City in September, and was felt as far away as Turkey and Pakistan.