A surprise nuclear deal with North Korea shows a renewed faith by US President Barack Obama in seeking diplomatic solutions, but resolving tensions over Iran may prove to be more complicated.

After years of friction and stormy exchanges, North Korea and the United States announced Wednesday that the communist state would freeze nuclear and missile tests along with uranium enrichment and let back in UN inspectors.

North Korea has repeatedly agreed and reneged on past agreements on its nuclear program. The Obama administration called on Pyongyang to honor the latest deal, praising the "important, if limited, progress."

The deal came amid a larger global focus on Iran, whose uranium enrichment has raised wide suspicions. Israel has led criticism of Iran's assertions that its program is for peaceful purposes, leading some observers to think that the Jewish state is considering military action against the Islamic regime.

As Prime Minister Benjamin Netanyahu prepares to discuss Iran next week at the White House, US military and civilian officials have cautioned against an attack on Iran. Obama's spokesman Jay Carney said Wednesday that military action would create "greater instability."

Israel quickly rejected parallels between Iran and North Korea. While much attention lies on whether or when Tehran will reach a point of nuclear capability, North Korea first tested an atom bomb in 2006.

"We should congratulate United States foreign policy... but we have to remember that what has happened in North Korea is too little, too late," Israel's deputy foreign minister Danny Ayalon said Thursday.

The North Koreans "have already crossed the threshold of nuclear capability and that's certainly not what we would want to see happen in Iran," Ayalon told Israeli public radio.

But Philip Yun, executive director of the Ploughshares Fund, which is opposed to weapons of mass destruction, said that one parallel between Iran and North Korea was that some policymakers in both countries believe that they need nuclear weapons for survival.

He pointed out that the United States, in its statement Wednesday, stated upfront that it "does not have hostile intent" toward North Korea and respected the communist state's sovereignty.

North Korea and Iran have had "a perception that we want to get rid of them. As long as that's the case, these people are going to do whatever they can to stay in power and they're going to resist with all their might all those attempts to remove them," Yun said.

Yun argued against an attack on Iran, saying that while it may temporarily set back the Islamic republic's nuclear program, "it's just going to harden their resolve, and we're basically creating what we're trying to prevent."

Yun acknowledged key differences between the two countries. North Korea enjoys strong support from neighboring China, weakening the impact of global sanctions, he said.

North Korea and Iran also find themselves in very different regions. Netanyahu has called Iran the biggest threat to Israel in its existence, pointing to bellicose statements by President Mahmoud Ahmadinejad.

North Korea has hostile relations with South Korea and Japan, but the two US allies have largely focused on managing tensions and have no realistic option of military action.

When Obama took office in 2009 with an offer to talk to US enemies, some policymakers believed that Iran, not North Korea, would be more likely to strike a deal. North Korea tested a long-range missile and a second atom bomb months into Obama's term.

Obama made a major appeal to Iran on the Persian New Year three years ago. The administration said that Iran failed to reciprocate and has since pursued tougher sanctions, as Obama's Republican rivals strongly criticized him for the initial outreach.

James Acton, a senior associate at the nuclear policy program at the Carnegie Endowment for International Peace, said that Iran and North Korea were vastly different but that they revealed a similar strategy by Obama.

"To the extent that there's an applicable principle, it's that there is often value in pursuing modest confidence-building steps rather than grandiose" efforts, Acton said.

"That's the Obama administration's strategy over Iran. The problem has been that Iran has just not been willing to strike a deal," he said.