Released North Korea Captives Bae and Miller Arrive in US

— -- Kenneth Bae and Matthew Todd Miller, two Americans who had been held prisoner in North Korea, arrived back in the U.S. tonight, after being freed through secret negotiations.

Bae and Miller flew back from North Korea on a U.S. military plane with National Intelligence Director James Clapper, who was involved in the negotiations, and landed at McChord Field, Joint Base Lewis-McChord, in Washington state shortly after 9 p.m. PT.

Bae, a Korean-American Christian missionary, had been held in North Korea since 2012 when he was accused of trying to overthrow the government. He was sentenced in April 2013 to 15 years of hard labor for allegedly trying to overthrow the North Korean state.

"I just want to say thank you all for supporting me and standing by me all this time," Bae said at a short news conference. "It is an amazing blessing to see so many people being involved to get me released."

He specifically thanked "all the people who supported my family," President Obama, the State Department, and the North Korean government.

When asked about his health, Bae only said he is "recovering."

His sister, Terri Chung, said he told her after getting off the plane, "I am so happy to be here, but my heart aches for the people of North Korea."

Miller, from California, was serving a six-year prison term for alleged espionage after reportedly tearing his visa upon arrival at the Pyongyang airport in April and requesting asylum. North Korea sentenced him in September saying he conspired to get arrested on purpose to research the human rights situation in North Korean prison.

Bae and Miller were the last two American detainees known to be held in North Korea after the release of Jeffrey Fowle last month.

The release of Bae and Miller only occurred after Clapper engaged in discussions with North Korean officials to secure their release, according to the State Department.

Clapper's involvement was the highest-level contact between the United States and North Korea since President George W. Bush said the country was part of the "Axis of Evil."

An official from the Obama administration told ABC News that the process of freeing the two Americans happened after a long effort.

"The actual sort of operation efforts have been playing out over several days," the official told ABC News.

The official added that the Americans' release was unrelated to negotiations over North Korea's nuclear program and that Clapper had been "prepared to listen to" whatever North Korean officials wanted to say.

North Korea has detained at least nine Americans since 2009.

The Associated Press contributed to this report.