The mother of an American man jailed in North Korea for unspecified anti-government crimes has expressed her gratitude to the North Korean government for allowing her to meet her son in Pyongyang, a news report said Saturday.

Kenneth Bae, a 45-year-old Korean-American known as a Christian missionary, was arrested in North Korea last November on charges of unspecified anti-government activities. In April, he was sentenced to 15 years of hard labor.

His mother, Bae Myung-hee, 68, flew to Pyongyang on Thursday to meet with her son who has been hospitalized since August.

The two met at the hospital on Friday.

"I feel frustrated seeing my son in hospital," Choson Sinbo, a pro-North Korean newspaper based in Japan, quoted the mother as saying. "My heart ached very much every time I saw reports on my son in prison and at the hospital."

The paper also quoted her as saying that her son had expressed hope that the U.S. government would take more active measures to secure his release.

"I'm grateful that the North Korean government has allowed me to meet my son on humanitarian grounds," she was quoted as saying.

In late August, Robert King, Washington's special envoy on North Korean human rights, planned to visit Pyongyang to negotiate Bae's release. 

However, North Korea abruptly canceled the invitation for King.

(Yonhap News)