A slight warming of relations between North and South Korea during the Winter Olympics might not be enough to lead to peace on the peninsula, US Defense Secretary Jim Mattis said on Sunday.

"It is too early to say if ... using the Olympics in a way to reduce tensions, if that is going to have any traction once the Olympics are over, we can't say right now," Mattis told reporters.

Read more: South Korea investigates cyberincident at Pyeongchang Olympics ceremony

Mattis questioned North Korean leader Kim Jong Un's intentions, specifically pointing to his decision to hold a military parade before the games.

"In the midst of all this, he ran a military parade that highlighted his ballistic missiles. That is a very strange time, if in fact he is trying to show a warming," the US defense chief said.

Others have voiced concerns that the North is attempting to use the Olympics to flout international sanctions, including bringing its 100-member-strong art troupe in by sea — causing the South to treat the ferry as an exemption to maritime sanctions.

Read more: In Seoul, Germany's Steinmeier warns Koreas that reunification needed luck, and hard work

Kim Yo Jong, the sister of North Korean leader Kim Jong Un, invited South Korean President Moon Jae-in for a summit in Pyongyang

North invites South for talks

His comments followed the news that North Korean leader Kim Jong Un's sister invited South Korean President Moon Jae-in to visit the North's capital Pyongyang.

Kim Yo Jong, the 30-year-old sister of the North Korean leader, said her brother hoped to host a summit with the South in an attempt to improve ties following a prolonged period of animosity.

Moon has not yet accepted the invitation, but he has been pushing for a diplomatic solution to the standoff over North Korea's missile and nuclear program.

US President Donald Trump's administration, on the other hand, has pursued a strategy of using harsh rhetoric and pushing through tough sanctions. Washington has also said that the North must first give up its nuclear program before any dialogue can occur.

Read more: North Korea welcomed to Olympic Village with national anthem

Mattis said that the diplomatic gestures between the two Koreas at the Olympics have not caused a rift between Washington and Seoul.

"On a political level in Seoul, there is no wedge that can be driven between us by North Korea," Mattis said

Should Moon take up Kim Jong Un's offer for a summit, it would be the first one to take place between the leaders of the two countries since 2007.

10 travel tips for South Korea Pyeongchang In the Taebaek Mountains on the east coast of the country there are many ski and snowboarding areas. From February 9th -25th Pyeongchang will host the 2018 Winter Games. It will mark the second time since the 1988 Summer Games that South Korea will host the Olympics.

10 travel tips for South Korea Seoul Seoul is the throbbing, futuristic capital of South Korea, with some 10 million inhabitants. The latest attraction is the High-Line-Park Seoullo 7017 – a disused overpass now serving as an urban walkway with restaurants, cafés and exhibitions. But there is also lots of history to be discovered in Seoul, like the Hanok districts with traditional houses and palaces of the Joseon-Dynasty.

10 travel tips for South Korea Bulguksa Temple Buddhist architectural art can be admired in countless temples. Located in Gyeongju is the temple complex Bulguksa, which with its distinctive pagodas has been listed a UNESCO World Heritage Site sine 1995. The Bulguksa compound along with other Buddhist temples participate in the Templestay program — which gives people the opportunity to live and meditate with Buddhist monks.

10 travel tips for South Korea Busan The port city in south-east is South Korea's most populous city after Seoul. Its beaches and the annual Busan International Film Festival (BIFF), one of the most renowned in Asia, make it so popular.

10 travel tips for South Korea Seoraksan National Park The national park attracts tourists all year round, but the main season for Seoraksan is autumn because the colors in the area are considered to be among the most beautiful in Korea. The red and yellow forest is interrupted by rocks and small mountain streams. On well marked paths visitors can climb Daecheongbong Peak, which at 1,708 meters (5,604 ft.) is the highest mountain in the national park.

10 travel tips for South Korea Demilitarized Zone Those wishing to better understand the history of North and South Korea should visit Panmunjeom base in the Demilitarized Zone (DMZ) between the two countries. The demarcation line, the border between North and South Korea, actually runs though the middle of the blue barracks. The barracks take turns in being accessible for visitors from both sides.

10 travel tips for South Korea Jeju Island South Korea's coast is full of little islands. The biggest of these is the volcanic island Jeju, which is a listed UNESCO natural World Heritage Site. Haenyeo, or female divers, hunt for squid, sea urchins and other shellfish along the coast, which they catch for the tourists. These specially trained divers do not require any oxygen or diving equipment.

10 travel tips for South Korea Hongdae Free Market Most shopping districts in Seoul provide a wide choice of electronics, clothes and cosmetics. There are also many markets. At the Hongdae Free Market, art students sell their creations every weekend. Department store fans should seek out the Shinsegae Center is Busan — which at 14 storeys high is one of the biggest department stores in the world.

10 travel tips for South Korea Bath Houses Traditional bath houses, or Jjimjilbang, are a popular place to relax for many Koreans. These bath houses, with different saunas, steam baths and pools are open 24-hours a day. Along with services like massages and peeling treatments, they often also offer sleeping rooms for overnight stays.

10 travel tips for South Korea Kimchi and Company Korean food is varied and healthy. The most common dishes on offer at street stalls or in restaurants is fermented Chinese cabbage — Kimchi — as well as rice and soup variations. Korean barbecues involve cooking meat, fish and shellfish at a small table grill. All that remains to be said is: "Jal meokkesseumnida"! (Enjoy your meal) Author: Lina Elter (sbc)



rs/jm (AP, Reuters)