Donald Trump’s proposal to meet North Korean leader Kim Jong Un was termed a “kind of propaganda or advertisement” by a senior North Korean official Monday.

The U.S. Republican presidential candidate had mentioned his willingness to talk to the North Korean leader to try to stop Pyongyang's nuclear program, in an interview with Reuters in New York last week. The proposal would have marked a major shift in U.S. policy toward the isolated nation.

So Se Pyong, North Korea's ambassador to the United Nations in Geneva, told Reuters, “It is up to the decision of my Supreme Leader whether he decides to meet or not, but I think his (Trump's) idea or talk is nonsense.”

He added, “There is no meaning, no sincerity.”

So, who has recently returned from Pyongyang after attending the first ruling party congress in 36 years, likened the move to President Barack Obama’s unfulfilled campaign promises to meet the leader of the Democratic People's Republic of Korea (DPRK). He said, “It's for utilization of the presidential election, that's all. A kind of a propaganda or advertisement.”

In the light of North Korea conducting a fourth nuclear test and launching a long-range rocket in January and February respectively, So, who also serves as North Korea's ambassador to the U.N.-backed Conference on Disarmament, said that his country was prepared to return to stalled six-party talks on its nuclear program. He said while China and Russia backed the idea, the U. S. and its allies South Korea and Japan reject it.

The country’s nuclear development has triggered tougher sanctions against it from the international community.

So claimed: “As a responsible nuclear state ... we will never use them first,” however, he also mentioned, “If the United States use their nuclear weapons first, then we have to use also that one.”

Reiterating North Korea’s stand on sharing nuclear technology, So said, “As a responsible nuclear state, we keep and observe the obligations of non-proliferation of nuclear technology.”