President Obama said Thursday he will seek the "toughest sanctions" against Iran over an alleged plot to assassinate the ambassador from Saudi Arabia in Washington, D.C., Reuters reported. Obama also said when it came to sanctions, he would not take any options off the table.

More from Reuters: "Obama, in his first public statement on the matter, called it part of a 'pattern of dangerous and reckless behavior' by Tehran, which has denied the accusations."

The State Department has been in "direct contact" with Iran about the alleged terror plot, CNN reported.

According to CNN:

State Department spokeswoman Victoria Nuland disclosed the contact at a news briefing Thursday. A senior administration official told CNN it occurred Wednesday and was initiated by the United States.

Nuland said she could not say who spoke to whom or where the meeting was held. She said it was not in Iran.

Iran has denied the allegations, with the country's permanent U.N. writing in a letter to U.N. Secretary-General Ban Ki-moon that Iran "strongly and categorically rejects these fabricated and baseless allegations, based on the suspicious claims by an individual. Any country could accuse other countries through fabrication of such stories. However, this would set dangerous precedents in the relations among States."

 

If it turns out Iran did plan the assassination plot, it would be considered an act of war.