Pope Francis is unlikely to visit North Korea in the winter, although it is difficult to predict when the trip will happen, the Cheong Wa Dae spokesperson said Tuesday.

President Moon Jae-in asked the pope during their meeting at the Vatican last week to visit North Korea to help foster peace on the Korean Peninsula. The pope responded that he would do so if he received an invitation from the North.

"Various efforts are under way, but it's difficult to predict the timing," Cheong Wa Dae spokeswoman Park Kyung-mee told KBS radio by phone from Europe where she was accompanying Moon. "The pope is from Argentina, which is a warm country, so my understanding is that it's difficult for him to travel in the winter."

Moon made the request to the pope at a time when he is also seeking international support for a declaration that will formally end the 1950-53 Korean War, which ended in an armistice, not a peace treaty.

The Moon administration hopes to use such a declaration to revive stalled peace talks with the North.

"A visit to North Korea by the pope, who is constantly praying for peace on the Korean Peninsula, is not a (publicity) event but a noble action in its own right," Park said.

"We would like it to be viewed on its own, rather than in connection with an end-of-war declaration or the Beijing Olympics," she added, referring to speculation that the government hopes to use a papal visit to draw the North to the negotiation table and set the stage for another inter-Korean summit on the sidelines of the Winter Olympics in February.

This was the second time Moon asked Pope Francis to visit North Korea.

No pontiff has ever visited the country before. (Yonhap)