RIYADH, May 2 (Reuters) -

Saudi Arabia's coast guard assisted an Iranian oil tanker with engine trouble off the coast of Jeddah in the Red Sea after Riyadh received a request for help from Iran, the state news agency SPA said on Thursday.

The vessel "Happiness 1" and its 26 crewmembers were found 70 km (43 miles) southwest of Jeddah Islamic Port, the agency said, adding that the captain had requested a tow due to "engine failure and loss of control".

The crew comprised 24 Iranians and two Bangladeshis, SPA said.

"The kingdom received an official request for help, through its permanent delegation to the United Nations in New York, from the Iranian charge d'affaires in the Iranian delegation," SPA quoted a coast guard spokesman as saying.

"All necessary precautions were taken for the safety of the crew and to ensure there is no environmental damage and to provide assistance," it added.

It was not clear if oil had spilled from the tanker.

The United States decided to end all waivers on Iranian oil imports by May 1 after which buyers of Iranian crude could face sanctions.

Regional foes Saudi Arabia and Iran are locked in to several proxy wars in the region.