The anti-American protests in South Korea have received most of the media attention, but demonstrations in support of U.S. troops are growing.

On Saturday, some 30,000 mostly Christian South Koreans pleaded to God for peace on the divided Korean Peninsula and in support of the U.S. military presence.

"Lord, we need U.S. troops," chanted the crowd, predominantly Protestant churchgoers, at the plaza before Seoul City Hall. "God, please help North Korea repent and stop developing nuclear weapons." Participants waved small South Korean flags and let loose thousands of green balloons into the overcast winter sky, shouting "Hallelujah!" Some held U.S. flags.

During a prayer blaring from loudspeakers, pastor Kil Ja-yeon asked God to keep U.S. troops in South Korea to deter communist North Korea, and thousands of followers jumped up and down chanting fervently, "My Lord, My Lord."

The pro-U.S. street demonstration, described by the Associated Press as "unusual," was really not so unusual, say South Korean participants. It was organized by the General Association of Christian Organizations, a major Christian umbrella group, and was prompted by rising international tension over North Korea's withdrawal Friday from the Nuclear Nonproliferation Treaty, a global nuclear arms control pact.

"We all prayed for the peace of ROK (Republic of Korea) and the world and announced to the north to stop what they are doing now," said Kay Cho, who attended the rally. "People are holding U.S. and Korean flag together and it seems all of them are hoping for the same thing – that we can get along with the U.S. and keep the U.S. Army in this country. This was really the biggest demonstration I've ever seen, but still very peaceful. It seems like the whole city of Seoul was covered with God's love."

But she said she was surprised the massive rally received almost no attention on South Korean television.

Communist North Korea shocked the global community in December by deciding to restart nuclear facilities that were frozen under a deal with the United States in 1994.

Organizers of Saturday's demonstration warned that widespread anti-American sentiment in South Korea might lead to the withdrawal of U.S. troops and endanger the country's security.

Moon Jong-won, 55, who participated in Saturday's rally, worried that young South Koreans failed to understand the North Korean threat.

"This is not a time for anti-American protests, but a time for an anti-North Korea and pro-peace movement," he told the AP.

Demonstrators held signs reading: "We oppose the anti-American movement" or "Lord, give North Korea real political change."

The rally was in contrast with a recent series of highly publicized anti-U.S. street demonstrations that were actually much smaller than Saturday's pro-American rally.

"We should not do things that hurt Americans' sentiment, especially at times like this," said Chung Jin-kyong, 34.

About 37,000 U.S. troops are stationed in South Korea, a legacy of the 1950-53 Korean War.