U.S. President Barack Obama says Washington is considering all options against Iran following a plot to assassinate the Saudi Ambassador to the United States.

Mr. Obama spoke to reporters during a news conference with South Korean President Lee Myung-bak in Washington.

He said it is clear that individuals within the Iranian government were aware of the plot, calling it part of a pattern of “dangerous and reckless behavior” by the Iranian government.

Mr. Obama also said Tehran has operated outside the accepted norms of international behavior for far too long and that the U.S. will make sure Iran “pays a price for this kind of behavior.”

The U.S. president said the first step will be to prosecute the individuals involved. He also said the U.S. will apply the toughest possible sanctions to further isolate the Tehran.