The leader of North Korea will not be coming to Moscow next month for the Victory Day celebration, President Vladimir Putin's spokesman announced Thursday.

The highly anticipated trip would have been Kim Jong Un's first foreign trip since taking power more than three years ago.

The Russian foreign minister had said in March that Kim was among 26 world leaders who had accepted invitations to take part in the May 9 celebration of the 70th anniversary of the Soviet Union's victory over Nazi Germany.

North Korea, however, had never confirmed that Kim planned to come.

Putin spokesman Dmitry Peskov told The Associated Press "internal matters" were preventing Kim from leaving North Korea. He did not elaborate.

On Wednesday, South Korea's spy agency told lawmakers that Kim had ordered the execution of 15 senior officials this year who were accused of challenging his authority.

Since taking over North Korea's leadership after the death of his father, Kim Jong Il, in 2011, Kim has removed members of the old guard through a series of purges — including the 2013 execution of his uncle, Jang Song Thaek, for alleged treason. Jang was married to Kim Jong Il's sister and was once considered the second most powerful man in North Korea.