Iranian Foreign Minister Ali-Akbar Salehi said that the new anti-Iran scenario initiated by the United States is "clumsy," the official IRNA news agency reported.

Washington will be compelled to apologize to Tehran for its "unfounded allegation" against Iran, the minister said, adding that "Our friends in the Persian Gulf region are familiar with these devilish conspiracies."

"We enjoy good ties with Saudi Arabia," Salehi said on the sidelines of Wednesday' cabinet meeting, noting that the best way to respond to Washington is disregarding and ignoring such allegations.

Iran's Deputy Foreign Minister Hassan Qashqavi denounced on Wednesday the US anti-Iran publicity campaign, saying that such measures are "aimed at sowing discord in the region," according to the English-language satellite Press TV.

Qashqavi deplored the U.S. allegations regarding Tehran's involvement in the plot and described the "unfounded claims" as part of a new "propaganda scenario" against Tehran, said the report.

Iran's Foreign Ministry summoned Swiss charge d'affaires on Wednesday to protest against Washington's accusations.