Seoul, Jan 10 (IANS): US President Donald Trump has formally congratulated North Korean leader Kim Jong-un on his birthday, South Korea's top presidential security adviser said on Friday, returning from his trip to Washington.

Chung Eui-yong, head of presidential palace's national security office, had a brief meeting with Trump at the White House during the trip, reports Yonhap News Agency.

Trump had some congratulatory words for Kim on the occasion of his January 8 birthday and asked South Korean President Moon Jae-in to deliver the message, according to Chung.

"As far as I know, the message was conveyed to North Korea in an appropriate manner," Chung told reporters at the Incheon International Airport here.

Friday's development comes amid ongoing tensions between the US and North Korea over Pyongyang's nuclear and missile programs, said Yonhap News Agency.

Last week, Kim said the world will witness North Korea's new strategic weapon, noting there is no reason to keep its self-imposed moratorium on nuclear and long-range missile tests.

Denuclearization talks have been stalled since the second summit between Kim and Trump ended without an agreement due to wide differences over how to match Pyongyang's denuclearization measures and Washington's sanctions relief.

The two sides held working-level talks in October 2019 but failed to narrow their differences.