Washington, Feb 18 (IANS): Neither the change in leadership in the US, nor sanctions imposed by the UN Security Council, will impede North Korea's economic and military advancement, according to an economist from Pyongyang.

Ri Gi Song, a researcher of the Institute of Economics at the Academy of Social Sciences, told CNN on Friday that sanctions weren't having an adverse impact on the country's military programme.

"No, the sanctions are not slowing down our nuclear and missile development," he said, adding "Rather we are going faster, we are increasing further the capability of our national defence with nuclear part as its main core."

The latest round of sanctions were imposed in November by the Security Council following the country's fifth nuclear test.

North Korea test-fired a new ballistic missile on Sunday, the first since President Donald Trump took office in January.

The launch was condemned by Japanese Prime Minister Shinzo Abe as "absolutely intolerable" during a press conference with Trump, and prompted responses from South Korea, China and Russia.

Speaking exclusively to CNN in Pyongyang, Ri said that the government would "continue to strengthen our nuclear capability as along as the United States continues its hostile policy against North Korea."

Ri said restrictions on North Korea's ability to sell raw materials, including coal, has not impeded the country's economic growth.

"The basic principle in terms of exporting raw materials is simply we don't promote the export of raw materials including coal," he said.

"As a result of that particular principle... we don't feel very much affected by the so-called restrictions in the export of coal."

He said the country was earning money from tech exports to Southeast Asia -- including precision computer numerical control (CNC) systems -- and processed raw materials like magnesite, graphite, and zinc products.

Regarding the US and its allies, he said: "They have to take... into good consideration, the fact that North Korea has now become a full-fledged nuclear power, a military power in the East."

Asked about the new Trump administration, Ri said while the US maintains a "continuous hostile policy", it does not matter which President is in the White House.

"Our advice would be for the new administration to be very considerate, to be very careful when they try to adopt new North Korea policy."

Ri also hit slammed US Defence Secretary James Mattis' recent visit to South Korea to discuss the Terminal High Altitude Area Defence (THAAD) missile system, which is being deployed to potentially intercept North Korean missiles.

"That particular visit and the commitment he made with the South Koreans is angering the local people here very much," the economist concluded.