Two American television journalists have been detained by the North Korean army at the Tumen River area near Yanji, China.
Acting spokesman Robert Wood told ABC News "the facts are not quite clear" what happened.
"We're trying to ascertain all of the facts. We do know that these two Americans were taken into custody," Wood said.
"There's a lot of contradictory information" Wood added, apparently backtracking on a statement provided earlier this morning as to the circumstances leading to the journalists' detainment.
He declined to provide any further details, saying that first "we want to make sure that we have a better understanding of what actually happened."
The US, he said, does not have any independent confirmation of what happened leading to the detainment.
Earlier the State Department had told ABC News that the pair were in China when they were detained and brought into North Korea.
"We are aware through reliable channels on the morning of March 17, that two American citizens were taken into custody across the Tumen River from China into North Korea by what appeared to be North Korean border guards," said State Department spokeswoman Julie Reside.
"We are working with the Chinese government in the area to get information on the whereabouts and welfare of the Americans in question. We have also been in touch with North Korean authorities to express our deep concern about this situation. We have also been in touch with our protecting power, the Swedish Embassy in Pyongyang," she said.
Reside declined to confirm the identities of the journalists, saying she does not have a Privacy Act waiver allowing her to do so.
The Rev. Chun Ki-Won, a human rights activist leading the Seoul-based Durihana Mission, told ABC News by telephone from New York that three journalists working for Current TV, a cable television network based in California, were in northern China to do a story on human trafficking of North Korean refugees.
He says he was informed that Laura Ling, a Chinese-American, and Euna Lee, a Korean-American, were detained in North Korea with their guide who is ethnic Korean of Chinese nationality. Current TV journalist Mitch Koss is reportedly safe.
"They came to me and I helped them find a group of North Korean refugees who have been kidnapped, enslaved and traded in the notorious black market in China," said Chun, who has helped thousands of North Korean refugees seek asylum in South Korea and the United States.
Chun had been in close contact with the team via phone while they were interviewing victims in Yanji, the capital city of Yanbian Korean Autonomous Prefecture, within Jilin province of northern China.
"The last I talked to them was on Tuesday 6 a.m. They were happy that they had successfully completed interviews and filming at that area and said they were on their way south to the Yalu River in Dandong."
Chun said that was the last he heard from them.
He had arranged for the journalists to get shots of the North Korean border from Dandong area because that is a tourist town "safe to shoot with video camera" where many get a glimpse of North Korean soil across the Yalu river.
The Tumen River in the north and Yalu River in the South along the China-North Korean border are two frequent crossing points for North Koreans seeking refuge.