TEHRAN, Iran — Iran says a guilty plea by a Texas man allegedly hired by the Islamic Republic to kill Saudi Arabia’s ambassador to the United States was the result of “psychological and moral pressure.”

The official IRNA news agency Saturday quotes Foreign Ministry spokesman Ramin Mehmanparast as saying Manssor Arbabsiar’s guilty plea Wednesday in a US court is proof that the case is a “ridiculous plot” against Iran since Arbabsiar originally pleaded not guilty last year.

At Wednesday’s hearing in a New York court, Arbabsiar was asked whether he intended to kill the Saudi ambassador, Adel Al-Jubeir. He said he did. He also said Iranian military officials based in Iran were involved in the plot.

Iran says it has no connection to Arbabsiar and that the US accusations have no “legal logic.”

Arbabsiar, a US citizen with an Iranian passport, suffers from bipolar disorder, according to his defense lawyers.

He was arrested Sept. 29, 2011, at Kennedy International Airport. A trial had been scheduled for January.