WASHINGTON (Reuters) - President Barack Obama pressed for greater religious freedom in China and offered prayers for U.S. prisoners in North Korea and Iran on Thursday during remarks at an annual prayer breakfast that highlighted his Christian faith.

Obama, who attended the breakfast at a Washington hotel with his wife, Michelle, used the high profile event to renew calls for the release of two men held by U.S. adversaries in Asia and the Middle East.

"We pray for Kenneth Bae, a Christian missionary who's been held in North Korea for 15 months ... His family wants him home. And the United States will continue to do everything in our power to secure his release," Obama said.

"We pray for Pastor Saeed Abedini. He's been held in Iran for more than 18 months, sentenced to eight years in prison on charges relating to his Christian beliefs."

Obama said religious freedom, protected by the first amendment of the U.S. Constitution, was under threat around the world and he singled out China and Burma, also known as Myanmar, as countries that needed to do better on the issue.

"When I meet with Chinese leaders - and we do a lot of business with the Chinese, and that relationship is extraordinarily important not just to our two countries but to the world - but I stress that realizing China's potential rests on upholding universal rights, including for Christians, and Tibetan Buddhists, and Uighur Muslims," Obama said to applause.

"GRATEFUL"

Obama, a Christian, does not talk frequently about his own faith, which was a big issue in the 2008 presidential campaign because of inflammatory remarks by his former Chicago pastor and due to false rumors he was a Muslim.

The president reflected briefly about his religious journey at the breakfast - highlighting his Christianity - and emphasized its role in his life as a community organizer in Chicago and his later career in public service.

"I'm grateful not only because I was broke and the church fed me, but because it led to everything else. It led me to embrace Jesus Christ as my Lord and Savior. It led me to Michelle, the love of my life, and it blessed us with two extraordinary daughters," Obama said.

"It led me to public service. And the longer I serve, especially in moments of trial or doubt, the more thankful I am of God's guiding hand."

The Obamas do not attend services regularly in Washington, though they occasionally walk across the street to a church near the White House on special occasions.

The national prayer breakfast is billed as an event where Republicans and Democrats set aside their political differences to focus on faith and religion.