ABC News’ Kirit Radia reports: The United States has released few details about its sensitive diplomatic efforts to gain the release of two American journalists detained by North Korea last week after they approached the border from China. But today, the State Department said it has received some assurance from Pyongyang that it will look after the Americans in custody. "We have formally requested through our protecting power in Pyongyang, the Swedish Embassy, that the Swedish government be provided with consular access to these two Americans. The North has assured us that the detainees will be well treated," acting spokesman Robert Wood said. Wood said that the US is aware of the espionage charges being levied against the Americans, but declined to say if the North Koreans conveyed that directly. Last week Laura Ling and Euna Lee, two American journalists working for Current TV, were detained by North Korean border guards as they walked along the frozen Tumen River that acts as the border between China and North Korea. The two were on a reporting trip to interview North Korean refugees in China. The State Department remains very tight lipped about the case citing the delicate diplomacy and, US officials concede in private, the unpredictability of the North Koreans. "I really don’t want to go into much more detail, because we’re trying to work this issue diplomatically and the less said from here, the better," Wood said today. The US has passed on messages to the North Koreans via the Swedish Embassy in Pyongyang, as well as through the Chinese government and directly to the North Koreans via their mission to the United Nations in New York. Part of the problem, officials said, is that the US has been unable to confirm where the Americans are being held. Reports say they are being held in a government guest house in Pyongyang run by the military intelligence agency.