WASHINGTON — The U.S. on Tuesday signaled a willingness to engage North Korea to secure the release of an American sentenced to 15 years of hard labor in the authoritarian country.

State Department spokeswoman Marie Harf would not say whether the U.S. might send a high-level official to Pyongyang to seek freedom for 45-year-old Kenneth Bae.

But she told reporters the U.S. is "willing to consider a number of different options to secure his release." She did not elaborate on what those options might be.

The department also announced Tuesday that Bob King, the U.S. special envoy for North Korean human rights issues, would be traveling to northeast Asia this month, but not to North Korea itself.

Bae is a tour operator and Christian missionary accused of "hostile acts" against North Korea. He has been detained nine months and was recently hospitalized.

Harf said the onus remains on the North Korean government to free Bae, who was sentenced in May. The U.S. has been calling for Pyongyang to grant amnesty and release him immediately.

Bae requested that a high-ranking U.S. official should come to North Korea and seek a pardon for his release, according to the latest video of him in detention, posted Tuesday by Choson Sinbo, a pro-North Korean newspaper based in Japan. It wasn't clear from the video whether Bae was speaking voluntarily.

The most recent case of an American detained then released by North Korea was Eddie Jun, a Korean-American from California, who was freed in May 2011. He was arrested for alleged unauthorized missionary work during several business trips to the country.

He was released on humanitarian grounds when the human rights envoy, King, visited Pyongyang to assess the impoverished North's food situation.

The State Department said in a statement that King is traveling to China, South Korea and Japan for discussions on human rights and humanitarian issues. His visit begins in China next Monday where he'll also meet officials from the government, the U.N. High Commissioner for Refugees and the World Food Program.