TEHRAN (Reuters) - Iran rejected U.S. allegations that two Iranians planned to assassinate the Saudi envoy to Washington, calling it a "untrue and baseless," the country's English language Press TV reported on Tuesday.

"Iran strongly denies the untrue and baseless allegations over a plan to assassinate the Saudi ambassador to Washington," Press TV quoted Foreign Ministry spokesman Ramin Mehmanparast as saying.

"It is a comedy show fabricated by America."

Mehmanparast also said the relationship between Iran and Saudi Arabia could not be harmed by "fabricating such baseless claims."

"Our relationship with Riyadh is based on mutual respect and such baseless claims will not succeed."

U.S. authorities broke up an alleged plot to bomb the Israeli and Saudi Arabian embassies in Washington and assassinate the Saudi ambassador to the United States, court documents and a U.S. official said on Tuesday.

The alleged plotters were identified as Manssor Arbabsiar and Gholam Shakuri -- both originally from Iran -- in the criminal complaint unsealed in federal court in New York City.

Political tension between Iran and Saudi Arabia has been increasing since Saudi forces intervened in March to help Bahrain's Sunni rulers crush pro-reform demonstrations backed by the Shi'ite majority.

Iran and the United State are at odds over the country's disputed nuclear program, which Washington and its allies say is a cover to build bombs.

Tehran denies this, saying it needs nuclear technology to generate electricity to meet its booming domestic need.

The United States and Israel, which Iran refuses to recognize, have not ruled out military action if diplomacy fails to resolve the row with Iran.

(Reporting by Zahra Hosseinian, Writing by Parisa Hafezi)