WASHINGTON, March 1 (Yonhap) -- External pressure alone will not be enough to convince North Korean leader Kim Jong-un to give up his nuclear ambitions, a former head of US Forces Korea (USFK) said Tuesday, stressing the need for what he called an internal pressure to change.

Retired Gen. Walter Sharp also pointed to the need for South Korea and the US to work with China to rid North Korea of its nuclear weapons.

"I personally believe that there's no amount of external pressure that is going to force Kim Jong-un to get rid of his nuclear weapons," the former USFK commander said in a webinar hosted by the Washington Times Foundation. Sharp served as USFK commander from 2008 to 2011.

"I think the only way that has any potential is to create both external pressure and internal pressure, and that will require information getting into North Korea," he added.

The US says it will seek a calibrated, practical approach toward North Korea, which many believe will include a willingness to make incremental concessions to North Korea, such as sanctions relief, in exchange for North Korean steps toward denuclearization.

Pyongyang, however, remains unresponsive to US outreach for dialogue. Denuclearization talks between the US and North Korea were last held in late 2019.

Washington sought to impose additional UN Security Council sanctions on North Korea after the recalcitrant state staged seven rounds of missile tests in January, the largest number of missile tests it conducted in a single month.

The US move at the UN Security Council was blocked by China and Russia -- both veto power-wielding permanent members of the council and close partners of North Korea.

The former USFK commander stressed the importance of China's cooperation to denuclearize the Korean Peninsula.

"It will require discussions with China about how reunified, denuclearized (Korean) peninsula is in China's national interest, much more so than where it is right now," said Sharp.

He also noted the North, even without its nuclear weapons, would pose a great threat to South Korea, adding it has the "largest artillery force in the world, many of them positioned within range of Seoul."

Sharp said that US-South Korean combined forces would still be able to stop North Korea should the North ever invade the South.

"I am very confident that the South Korean military and the US and all those that would come to fight, we would be able to stop North Korea from taking Seoul. I'm confident in that," he said.

"But I also unfortunately believe that if a full scale attack like that took place, the number of casualties in the city of 28 million, which the greater Seoul metropolitan area is, would be horrific," added Sharp. (Yonhap)