U.N. Secretary-General Antonio Guterres said Sunday he is planning to visit Japan by year-end to discuss with Prime Minister Shinzo Abe a range of issues including North Korea's nuclear program.

"Japan is a very important partner of the U.N. I am looking forward to that visit and talking about everything," Guterres said in an interview aboard the official U.N. aircraft. He is expected to underscore the need for a political solution to the North Korean issue.

North Korea has continued testing nuclear weapons and developing missiles despite U.N. sanctions.

Abe and Guterres will also likely discuss global warming, U.N. reforms and sustainable development goals toward eradicating poverty and inequality.

The visit by the U.N. chief will be the first since Guterres assumed his post in January. The visit is expected to happen in December when the government will host an international meeting on health and medical issues.

Abe met with Guterres last month at U.N. headquarters in New York, expressing hope that he would visit Japan at an early date.

In the interview, Guterres also said he wants to visit Hiroshima and Nagasaki in the future, adding he has no plan so far to visit the two cities devastated by U.S. atomic bombings in 1945.

"I am very happy to go back," said Guterres, who has previously visited the cities.