The United States needs to consider package talks with North Korea on its nuclear program and a peace treaty as an alternative to the failed denuclearization first policy, an American expert said Thursday.

The new approach is worth trying despite some risks, including the North's demand for an immediate end to the South Korea-U.S. alliance, according to Joel Wit, a former Washington negotiator with Pyongyang.

Speaking at a forum in Seoul, Wit pointed out that there is a consensus that the Obama administration's policy on North Korea has failed.

But there is no consensus on what to do as an alternative, said Wit, who has long followed the North Korea issue. He is now a senior fellow with the U.S.-Korea Institute at the Johns Hopkins University School of Advanced International Studies.

A dilemma is the sequencing. The U.S. wants North Korea's denuclearization in advance, while Pyongyang says a peace treaty should precede it to replace the 1953 Armistice Agreement that effectively ended the Korean War.

Wit called for renewed diplomacy for talks on an "unconditional peace treaty along with denuclearization negotiations."

"It's complicated and difficult but probably the only path forward that could make significant progress by affecting core security concerns and political relations," he said. "And I think the risks of adopting this alternative track are not that great."

On worries that Pyongyang would demand the withdrawal of U.S. troops from the peninsula at the beginning of the talks, he said North Koreans are "not stupid" as they know it would mean an end to the process.

"It may be a litmus test to see where they are in their thinking," he added during the session hosted by the Asan Institute for Policy Studies.

He argued the Kim Jong-un regime is winning the diplomatic battle with the U.S. government.

For the past two decades, American presidents presented a choice to North Korea between giving up its nuclear weapons program and establishing better ties with the international community.

Today, however, Kim is increasingly offering his own choice between "accommodation and acceptance" of a nuclear-armed North Korea or tensions and instability on the peninsula, said Wit.

Kim's aggressive moves are based on the rapid expansion of the North's nuclear and missile capability, he added.

The secretive communist nation is believed to have 10-16 nuclear weapons - six to eight plutonium bombs and four to eight uranium ones.

Wit predicted the North will increase the number to as many as 100 by 2020 under the worst-case scenario.

As for speculation about why Pyongyang has not fired a long-range rocket recently, he said there was no evidence of its preparation for such a launch other than media-led guesswork. (Yonhap)