The Democratic People's Republic of Korea (DPRK) has accused the United States of "disturbing" the reconciliation process between Pyongyang and Seoul, by sending nuclear powered aircraft carrier strike groups in the vicinity of the Korean Peninsula.

In a letter sent to UN Secretary General Antonio Guterres on Wednesday, DPRK's Foreign Minister Ri Yong Ho said "good results are borne in the inter-Korean dialogue," but Washington is "seeking to intentionally aggravate the situation by introducing the strategic assets including nuclear powered aircraft carrier strike groups into the vicinity of the Korean Peninsula at a time when north and south of Korea are charting a course of peace together."

Ri accused the US of preparing for "preemptive strike" against the DPRK and planning to conduct a large-scale joint military drill with South Korea, after the PyeongChang Olympic and Paralympic Winter Games in February and March.

The DPRK's foreign minister called on the UN Security Council to welcome the process of inter-Korean reconciliation and discourage the "neighboring countries" from undermining it.

After a year of tensions on the peninsula over Pyongyang's nuclear weapon and missile program, the DPRK and South Korea conducted rare talks in January to facilitate the DPRK's participation in the PyeongChang Games. 

According to the agreement between the two sides that has been approved by the International Olympic Committee (IOC), delegations of the DPRK and South Korea will march together at the opening ceremony next Friday, and the two sides will form a united women's ice hockey team to compete in the Olympics. 

On Thursday, the DPRK's athletes arrived at the Olympic Village in South Korean city Gangneung, where the DPRK's national flag was raised.

In addition, the DPRK's 140-member Samjiyon Orchestra will hold two concerts in South Korea.

The US, however, has been suspicious about Pyongyang's motives behind its overture for talks. Amid concerns that DPRK leader Kim Jong Un is trying to drive a wedge between Seoul and Washington, US President Donald Trump has decided to send his deputy Mike Pence to attend the games to prevent the DPRK from "hijacking" it, a White House official said Tuesday.

Meanwhile, multiple US media outlets have reported that Pyongyang is planning to celebrate the 70th founding anniversary of its armed forces with a massive military parade next Thursday, just one day ahead of the opening of the Winter Olympics. 

Commenting on the DPRK's participation in the games and its plan to stage the military parade, Wang Chong, a senior fellow from Chinese think tank Charhar Institute, said Pyongyang is "sending mixed signals". The country wants to tell the world that it is a "peace-loving nation," but at the same time it does not want to "lose face" in front of its own people, he added.

Joseph Yun, US special envoy on the DPRK, said on Thursday that all options remain on the table for solving the nuclear standoff, but he does not think Washington is "close to" the military option.