As the U.S. and Iran inch toward reconciliation, North Korea, another rogue nuclear aspirant, is vying for Washington’s attention in hopes of escaping from isolation and ease international sanctions.

Pyongyang has recently stepped up its peace offensive, expressing its willingness to negotiate with the U.S. and resume the long-stalled six-party talks on its nuclear programs.

But its overture, backed by its sole ally China, has been given the cold shoulder by the U.S. Washington remains skeptical about the sincerity of the North, which has repeatedly reneged on agreements, most recently in 2012.

Pyongyang’s diplomatic quagmire was highlighted by its conspicuous absence from U.S. President Barack Obama’s crucial address at the U.N. General Assembly on Tuesday. Not a word about the North was uttered during Obama’s 40-minute which focused mainly on the Middle East.

This is in stark contrast to the efforts by U.S. and Iran to deal with Tehran’s nuclear programs since moderate Iranian President Hassan Rouhani took office last month.

Pundits have long rehashed comparisons between Pyongyang and Tehran due to their military ambitions and alleged covert partnership.

After years of tension, Rouhani launched a new course to improve ties with the U.S. and the West.

Speculation over the first encounter between the two leaders at the U.N. this week had raised hopes for a turning point in the long-festering nuclear standoff.

Though no handshake materialized apparently due to domestic political hurdles in Tehran, it is becoming increasingly clear that the two foes began to embrace diplomacy to break the gridlock.

U.S. Secretary of State John Kerry and his Iranian counterpart Mohammad Zarif will meet on Thursday in New York in what will be the first encounter between the two countries’ top diplomats since the Islamic Revolution in 1979.

They will be joined by their counterparts in the so-called P5+1 talks which also involve China, Russia, Britain, France and Germany.

A Seoul official who has been closely following up on the matter said, “a deal (between Washington and Tehran) would be not as easy as it may look, but I think it is possible for them to come up with something similar to one that was sealed with North Korea on Sept. 19, 2005.”

In a landmark 2005 deal of the six-party talks, Pyongyang agreed to relinquish its nuclear weapons program in return for economic, security and energy support.

But little progress has been made and the talks were last held in December 2008 as the communist state reneged by testing its atomic devices and long-range missiles, starting in 2006.

Unnerved by the perceived sign of reconciliation, Israeli Prime Minister Benjamin Netanyahu cited the North Korean case to discount Tehran’s charm offensive. Israel is Iran’s archrival and another key player in the nuclear dispute.

“Iran thinks that soothing words and token actions will enable it to continue on its path to the bomb,” he said after Obama’s speech.

“Like North Korea before it, Iran will try to remove sanctions by offering cosmetic concessions while preserving its ability to rapidly build a nuclear weapon at the time of its choosing.”

Any hasty breakthrough, Israeli officials say, will likewise buy time for Tehran to beef up its nuclear capability while taking advantage of eased sanctions and concessions from the West.

Both North Korea and Iran insist on their right to peaceful nuclear energy development.

Washington officials have drawn a line between the two cases, citing the two countries’ respective nuclear capability.

“The comparison is simply that they are two nations that have not abided by international nonproliferation norms,” Ben Rhodes, deputy national security adviser at the White House, told reporters on Monday.

“But the fact of the matter is North Korea already has a nuclear weapon. … And Iran does not yet have a nuclear weapon.

“And that’s all the more reason why we need to take steps to prevent Iran from getting a nuclear weapon so that we’re not presented with the type of situation that we have in North Korea where you’re seeking to denuclearize a country that has already crossed that threshold.”

His remarks were backed by a new study by two U.S. experts that argued that North Korean scientists have probably mastered the technology to produce key components of gas centrifuges used to enrich uranium for atomic bomb fuel.

They include uranium hexafluoride, vacuum pumps, ring magnets, frequency inverters, maraging steel, and computer numeric controlled flow-forming machines.

The apparent development in Pyongyang’s nuclear program would make it more difficult for Washington to resume negotiations and the international community to deter further progress, experts say.

The North codified its nuclear-armed status in late May and has demanded nonproliferation talks, a claim unacceptable for South Korea and the U.S.

Pyongyang has recently been calling for high-level dialogue with Washington and a restart of six-nation denuclearization talks with the U.S., South Korea, China, Japan and Russia.

But Seoul and Washington remain unwavering in their calls for preemptive, stronger commitments from Pyongyang than agreed in the so-called Leap Day deal for any fresh round of talks.

On Feb. 29, 2012, the North agreed to put a moratorium on its nuclear enrichment program, cease atomic and missile tests and allow IAEA inspectors in exchange for 240,000 tons of food aid from the U.S.

“Export controls, sanctions, and interdiction will not be able to stop North Korea’s enrichment of uranium for nuclear weapons,” said Joshua Pollack of the Science Applications International Corp., one of the analysts who presented the findings on Wednesday at a conference hosted by the Asan Institute for Policy Studies in Seoul.

“That raises serious questions about whether there is, or can be, a viable strategy for nuclear rollback. If a denuclearization agreement is reached with North Korea, either soon or in the more distant future, how can it be verified?”

Seoul officials appeared cautious about the findings, saying there were “various views on North Korea’s nuclear capability and technologies.”

“Our position remains unchanged that we cannot accept North Korea as a nuclear weapons state,” a government official said on condition of anonymity due to the sensitivity of the matter.

“If they were to get back to the negotiating table, the North should first show sincerity through action, not empty words.”

By Shin Hyon-hee (heeshin@heraldcorp.com)