TEHRAN, Iran - Iran will send the United States 20 million barrels of crude oil to help it overcome the devastation of Hurricane Katrina, if Washington waives trade sanctions, a senior Iranian oil official said.

In a gesture that mirrors American aid offers after a devastating 2003 earthquake in Iran, Tehran's envoy to the Organization of Petroleum Exporting Countries announced his government would ship up to 20 million barrels of oil to the U.S., state radio reported late Tuesday.

"If U.S. sanctions are lifted, Iran is prepared to send that quantity of oil to America," the radio quoted Hossein Kazempour as saying.

U.S. officials couldn't be reached for comment, but there were no signs that the U.S. policy toward Iran was about to change. Last week, the Iranian Foreign Ministry offered to send relief supplies to the American Red Cross; no response had been received.

Iran's offers reciprocates the goodwill that the United States displayed after an earthquake flattened the southeastern Iranian city of Bam in 2003, killing more than 26,000 people. The United States flew in emergency supplies, which were gratefully unloaded at an Iranian airport.

The Bam gesture did not, however, lead to an improvement in relations.

The United States and Iran have had no diplomatic relations since militants stormed the U.S. Embassy in Tehran and held its occupants hostage in 1979. Washington then imposed a range of sanctions on Iran.

MEXICO CITY - Radio talk shows and newspapers here buzzed with excitement over news that Mexico, long on the receiving end of U.S. disaster relief, was sending a hurricane aid convoy to help its larger, richer and more powerful northern neighbor.Carrying water treatment plants, mobile kitchens and supplies to feed victims of Hurricane Katrina, the army convoy bound for Houston will be the first Mexican military unit to operate on U.S. soil since 1846.The convoy has "a very high symbolic content," said Javier Oliva, a political scientist at Mexico's National Autonomous University. "This is a very sensitive subject, for historic and political reasons."Large Mexican flags were taped to many of the 35 olive-green Mexican Army trucks and tractor trailers as they rumbled northward toward the border today. The convoy was due to cross into Laredo, Texas, early Thursday, President Vicente Fox's office said.