Republican vice presidential nominee Rep. Paul Ryan on Sunday criticized the Obama administration's response to the deadly attack on the U.S. consulate in Libya, saying it is just part of a larger “unraveling” of its foreign policy.

“Their response was slow. It was confused, it was inconsistent,” Ryan said on “Fox News Sunday.” “It’s part of a bigger picture of the fact that the Obama foreign policy is unraveling literally before our eyes on our TV screens.”

Ryan made his remarks just days before Republican presidential nominee Mitt Romney is expected to give a major foreign policy speech.

“What Mitt Romney's going to do is lay out a very different vision for foreign policy -- one that is a policy of American strength versus what I would articulate or claim the president's policy is one of weakness,” Ryan said.

The Sept. 11 attack on the U.S. consulate in Benghazi, Libya, killed a U.S. ambassador and three other Americans. The White House initially said the attack was a “spontaneous” response to a anti-Islamic video trailer but has since acknowledged it was a planned terror attack.

The Wisconsin congressman on Sunday also called the recent violence in the Middle East “the ugly fruits of the Obama foreign policy,” arguing that 20,000 people have been killed, Iran is closer to a nuclear weapon and Russia is “thwarting us at every stage.”

Ryan called Iran “the biggest threat we have today” and said the big issue is Obama’s credibility.

“The Ayatollahs in Iran, they have to make a decision to stop pursuing a nuclear weapon and pursue a peaceful resolution,” he said. “I would argue that they're not doing that because the president doesn't have credibility."

Ryan also said he and Romney have repeatedly said the U.S. has to stop Iran’s nuclear weapons capability and that a Romney-Ryan administration would not put “daylight between our allies, especially Israel.”

He also said the president has “moved his rhetoric a bit to look more like ours, and that's good, but the problem is it's built upon a mountain of non-credible actions.”