Secretary of State John Kerry said Monday that the press is overestimating the amount of unfrozen revenues that will go to Iran as part of the Iran nuclear deal, and said it's roughly half to a third of those estimates.

Press reports since the fall have said Iran would get $100 billion to $150 billion in unfrozen revenues once sanctions are lifted, something that happened over the weekend. But Kerry on MSNBC Monday rejected the idea that Iran would get that much.

"That is a fictional number. I don't know where it comes from," he told MSNBC's "Morning Joe."

"They will get about $55 billion over a period of time," he said.

Kerry also downplayed the idea that Iran would be able to use those billions to promote terrorism around the world. Instead, he argued that Iran has pressing domestic needs to take care of.

"Iran has well over five hundred to seven, eight hundred million dollars of requirements just to build its oil drilling capacity back, just to begin to build its infrastructure back," he said. "They have massive needs within their country, and we will be able to track where this money is going, what's happening with it."

"If indeed the [Revolutionary Guard] continues activities which have been sanctionable in the past, they will be inviting further sanctions," he added.

The Wall Street Journal and others reported back in the fall that about $100 billion in frozen Iranian oil revenue would be freed up by the deal, and GOP candidates for president like Donald Trump have put the number at $150 billion.

Kerry broadly defended the deal Monday morning, and said "the world is safer today" now that it's been implemented. He said before the deal, Iran had a two-month breakout time for building up to a dozen nuclear weapons, but said now Iran's breakout time is closer to a year.

Kerry said Iran was inevitably headed toward becoming a nuclear state, but now has rolled back its program and has shipped most of its nuclear material out of the country.