Iran has the capacity to produce nuclear weapons and is prepared to change its policies on using them if faced with an existential threat, an adviser to its supreme leader said Friday in the latest bellicose statement from the country amid its high-stakes tit-for-tat with Israel. 

Kamal Kharrazi also said the country is likely to increase the range of its ballistic missiles.

“If an existential threat arises, Iran will modify its nuclear doctrine, we have the capability to build weapons and…