North Korea is racing ahead with development of nuclear weapons and hopes to have them ready by the end of next year, CNN quoted a high-profile diplomat who defected to South Korea.

Thae Young-ho, formerly the No. 2 person at the North Korean Embassy in London, said political uncertainty in the United States and South Korea could give North Korean leader Kim Jong-un "an apt time" to develop the weapons.

CNN said his comments came in a news briefing reported by the Yonhap News Agency.

"Due to domestic political procedures, North Korea calculates that South Korea and the U.S. will not be able to take physical or military actions to deter North Korea's nuclear development," Thae said.

He said North Korea has no intention of abandoning its nuclear program even if it is offered large sums of money. Thae said the nation was pushing ahead "at all costs."

"Following the ruling party congress in May, Kim Jong-un made it a party policy to finish nuclear development within the earliest time possible," he said.

He comments followed President-elect Donald Trump's words the U.S. would look to "strengthen and expand" its nuclear capability.

It was Thae's first appearance with the media since escaping his post in London and taking refuge in South Korea in July, CNN noted.

Meanwhile, NBC News reported a senior North Korean official said his nation is targeting mainland America with a nuclear weapons program it will not give up.

He warned American policies, including sanctions, have backfired, according to the network news.

• North Korea Says South Committing 'Terror' By Luring Defectors
• Trump Says US Nuclear Arsenal Must Be 'Greatly' Expanded