Colin Powell with Hillary Clinton
Colin Powell with Hillary ClintonReuters

In a private email message sent last year and leaked this week by hackers, former US Secretary of State Colin Powell discussed Israel's nuclear weapons capability with a friend, saying the country has 200 warheads.

In the March 2015 exchange from his personal Gmail account, Powell was discussing Prime Minister Binyamin Netanyahu's speech to Congress that day, and the possibility that Iran could build a nuclear bomb.

"Iranians can't use one if they finally make one," Powell wrote to Democratic donor Jeffrey Leeds, a hedge-fund founder who serves on the board of the Colin L. Powell School for Civic and Global Leadership at the City College of New York. "The boys in Tehran know Israel has 200, all targeted on Tehran, and we have thousands."

Powell, a retired Army general who has served as White House national security adviser and chairman of the Joint Chiefs of Staff, told The Associated Press on Friday through a spokeswoman he was referring to public estimates of Israel's nukes.

"Gen. Powell has not been briefed or had any knowledge from U.S. sources on the existence and or size of an Israeli nuclear capability," the statement said. "He like many people believe that there may be a capability and the number 200 has been speculated upon in open sources." It added: "This email was written 10 years after he left government and has not received briefings on classified matters."

Israel has a long-standing policy of ambiguity regarding its nuclear weapons capability.