"I have received correspondence from the United States, Iran and also the Saudi government," Ban said.
The United States said last Tuesday it had uncovered a plot by two men with links to Iran's security forces to assassinate Saudi Ambassador to the United States Adel Al-Jubeir by planting a bomb in a Washington restaurant.
One of the men, who allegedly paid a US undercover agent posing as a Mexican drug cartel hit man to carry out the assassination, has been arrested while the United States says the other is in Iran.
Ban declined to comment on whether Iran was likely to face further sanctions. US President Barack Obama has promised to press for "the toughest possible sanctions" against Iran, and said he would not take any options off the table.
Iran's foreign minister on Monday offered to look into charges that agents of his government were involved in the plot, if the US provides enough information.
The statement by Ali Akbar Salehi was the first indication that Iran might cooperate with the investigation, though other officials maintained a steady stream of ridicule and rejection of the charges.
In Switzerland on Monday, Iran's Parliament Speaker said American officials are playing a child's game and have insulted his nation with the accusations.
Iran's semiofficial news agency ISNA quoted Salehi as saying Iran would deal with US claims patiently, even if the case is seen as a fabrication. He said Tehran has asked Washington to provide information about those arrested, so that Iran can examine their background.
