A missionary organization said Friday that a pilot who was kidnapped while working for the group in Niger last year was in “good health” after his release. Missionary pilot Kevin Rideout was kidnapped from his home in Niamey, the capital of Niger, in October. A U.S. official said Friday that Rideout had arrived at Ramstein Air Base in Germany and was undergoing a medical evaluation. Like others in this article, the official spoke on condition of anonymity to discuss operational matters. Rideout’s organization, called Serving in Mission, said in a statement that he would soon be reunited with his loved ones. “We are grateful to confirm that our good friend and brother in Christ, Kevin Rideout, has been released,” the statement said. The mission noted that he was in “good health under the care of U.S. officials” and would soon be reunited with his wife, Krista; his four children; and his extended family. “Krista and the rest of Kevin’s family are deeply grateful for the prayers offered on his behalf by people around the world during his captivity,” the statement added. Another U.S. official said Thursday that Rideout’s release, previously reported by The New York Times, was not the result of a military rescue operation but “by other means,” without offering further details. The official linked Rideout’s release to US military pressure on the Islamic State in Nigeria, Niger’s southern neighbor, in recent months. In May, President Trump said U.S. and Nigerian forces had killed Abu Bilal al-Minuki, a senior Islamic State leader in Lake Chad, a region at the intersection of four countries, including Nigeria and Niger. The official said that raid had helped influence the kidnappers’ decision to release Mr. Rideout. It was still unclear how and where he was released, U.S. officials previously said, and it was also unclear which group held him at the end of his captivity. Rideout’s release had been a top priority for the White House and the Army’s Africa Command. President Trump celebrated the release of Rideout, whom he called a “wonderful Christian missionary,” in a social media post on Friday. “Kevin, the United States of America looks forward to welcoming you to CASA,” he wrote. “I’m glad I helped!” In May, French journalist and researcher Wassim Nasr, who has been following jihadist groups in the area for several years, said Rideout was detained in Ménaka, a region of Mali just across the border from Niger. That area is mainly controlled by a local branch of the Islamic State. For years, Mali and Niger have been fighting insurgents affiliated with Al Qaeda and the Islamic State. In April, al Qaeda-linked militants launched coordinated attacks across Mali, capturing a major city and killing the country’s defense minister.