President Barack Obama is calling the alleged Iranian plot to assassinate Saudi Arabia's ambassador to the United States a flagrant violation of U.S. and international law.
The president's comments came in a telephone conversation Tuesday with Ambassador Abdel al-Jubeir.
A White House statement said the president expressed U.S. solidarity with Saudi Arabia and reiterated the U.S. commitment to ensure the security of diplomats serving in the United States.
Secretary of State Hillary Clinton said on Tuesday that the U.S. is consulting with friends and partners about how to send a strong message to Iran and further isolate it from the international community.
President Obama attended a meeting of his national security team Tuesday morning to thank them for their exceptional work in disrupting the plot.
The White House said Mr. Obama was briefed on the investigation last June.
There has been no formal White House comment on remarks by the head of the House of Representatives Permanent Select Committee on Intelligence, Republican Representative Mike Rogers.
Rogers said in media interviews it was clear the plot was tied to the highest levels of the Iranian government. In a written statement he said it "underscores the need for concerted international unity to confront Iran."
The Iranian government has denied any involvement in the alleged assassination plot.