North Korea has reopened a vital line of communication with South Korea, raising hopes of a diplomatic thaw days after Kim Jong-un said he would consider sending his country’s athletes to next month’s Winter Olympics, to be held just south of the border.

Hours after Donald Trump again baited the North Korean leader on Twitter – this time with a boast about the size and efficacy of his nuclear button – Pyongyang said it would resume communications at the truce village of Panmunjom at 6.30am GMT on Wednesday.

According to the announcement, broadcast on state TV, the order to reopen formal communications along the border was given by Kim. "By upholding a decision by the leadership, we will make close contact with South Korea in a sincere and faithful manner,” said Ri Son-gwon, the head of the North Korean agency that handles inter-Korean affairs.

He said Kim "highly appreciated and welcomed” the positive response by South Korea’s president, Moon Jae-in, to his New Year’s Day offer of talks on North Korean participation in the Olympics.

"The leader stressed that whether inter-Korean ties can be improved totally depends on North and South Korea,” Ri said.

The Pyeongchang Games open on 9 February and take place 50 miles (80km) south of the heavily armed border separating the two Koreas.

On Tuesday, Moon had welcomed Kim’s unexpected overture as a "positive response” to Seoul’s belief that the Olympics should represent a "groundbreaking opportunity for peace”.

On Wednesday, Yoon Young-chan, a spokesman for Moon, said the decision to reopen the hotline had "significant meaning” because it could lead to regular communication between the nations.

The South Korean news agency Yonhap cited the Pyongyang’s committee for the peaceful reunification of Korea as saying it wished to use the line of communication to discuss practical matters, such as the participation of North Korean athletes at Pyeongchang.

South Korea has suggested holding high-level talks next Tuesday at Panmunjom, an area of the demilitarised zone where blue UN huts have traditionally been used to host cross-border negotiations. The talks would be the first direct negotiations between the states since a vice-ministerial meeting in December 2015.

In his statement, Ri did not indicate whether North Korea would accept Seoul’s offer.

The prospect of dialogue, after a year of rising tensions over Pyongyang’s nuclear and ballistic missile programmes, received a mixed response from the US.

Agencies