New Delhi, Feb. 1 -- Iran's Supreme Leader Ayatollah Ali Khamenei on Sunday warned that any attack by the United States would spark a "regional war" in the Middle East, ratcheting up tensions amid President Donald Trump's threats to attack the Islamic Republic.

"The Americans should know that if they start a war, this time it will be a regional war," Khamenei said in comments on Iranian state television, as per news agency Associated Press.

"We are not the instigators and we do not seek to attack any country. But the Iranian nation will deliver a firm blow to anyone who attacks or harasses it," the Iranian Supreme Leader was quoted as saying.

The comment by the 86-year-old Iranian leader, is according to AP, the most direct threat he's...