(CNN) -- After nearly three months of maintaining their silence, the families of two U.S. journalists detained in North Korea are taking to the airwaves this week to lobby for their release as the women go on trial Thursday.
Analysts said they think Pyongyang will convict the journalists, Laura Ling and Euna Lee, on spying charges and hand down long sentences in the communist nation's labor camps.
"I suspect they will be used as some kind of pawn in future negotiations between North Korea and the U.S. to gain concessions," said Brian Bridges, a professor at Hong Kong's Lingnan University who specializes in the politics and foreign policies of the two Koreas.
The United States is among several countries that have condemned the North for last month's underground nuclear test and short-range rocket launches.
U.S. State Department deputy spokesman Robert Wood said Monday that North Korea should not link the fate of the two journalists to the international standoff over its nuclear program.
"The whole nuclear issue a separate one," he said.
Calling the case a "high priority" for President Obama and Secretary of State Hillary Clinton, Wood said, "We're going to continue our efforts to try to gain their release. We're going to continue to do all we can to see them back with their families."
Ling and Lee are reporters for California-based Current TV, the media venture of former Vice President Al Gore.
The pair was reporting on the plight of North Korean defectors living along the China-North Korea border when they were taken into custody March 17.
North Korea said the reporters had entered the country illegally. The women were accused of "hostile acts" and charged with spying.
Until now, their families have not commented publicly, citing the sensitive nature of the case.
But this week, the families will launch a media blitz with numerous television appearances, including Monday on CNN's "Larry King Live."
At the same time, supporters are using the social-networking site Facebook to organize nationwide candlelight vigils Thursday, when the trial is set to begin in Pyongyang.
The mounting movement is reminiscent of the one waged for Roxana Saberi, an American journalist whom Iran released last month after originally sentencing her to eight years in prison for espionage.
"Our families have been very quiet because of the extreme sensitivity of the situation, but given the fact that our girls are in the midst of a global nuclear standoff, we cannot wait any longer," Laura Ling's sister, Lisa, wrote on a Facebook page for the detained journalists.
Lisa Ling, a special correspondent for CNN, added: "Please help us urge both our government and North Korea's to resolve this humanitarian issue. Help us stand up for truth and two girls who just wanted to tell the world a story."
The North Korean Constitution calls for public trials, except under some circumstances, and says the accused have the right to a defense.
KCNA, the North Korean state-run news agency, has said that the reporters were allowed consular contact and that their treatment was governed by international laws.
The U.S. State Department also said it received reports that the women were being treated well.
The Swedish ambassador to North Korea was allowed to see the two journalists Monday, Wood said. Sweden is the protecting power for the United States in North Korea because the two countries, which fought on opposite sides during the three-year Korean war in the 1950s, do not have diplomatic relations.
The ambassador met separately with the two journalists, Wood said. The ambassador also saw the women March 30 and May 15.
As recently as early May, Clinton held out hope that the case would be resolved soon.
"We believe the charges are baseless and should not have been brought and that these two young women should be released immediately," she said. "But the fact they they are now going to have some process, we believe, is a signal that there can be and, I hope will be, a resolution as soon as possible."
But such optimism changed after North Korea conducted its nuclear test last week. The U.N. Security Council is considering a resolution to condemn the move.
The tests have cleared the way for the United States and other countries to impose new punitive measures against a country desperate for food and energy assistance.
"At some stage, there will have to be some negotiations over the nuclear issue, the missile issue," said Bridges, the Lingnan University professor. "And I suspect the North will allow them to leave the country, but they will expect something as part of the deal -- if not explicitly, then implicitly."
In a letter Laura Ling sent to her family, she asked them to remain strong.
"When I first got here, I cried so much. Now, I cry less," the letter read. "I try very hard to think about positive things. ... For example, I think, 'I'm lucky I made it through another day.' I'm lucky my family is working so hard to get me released."
Still, said Ling's husband of 12 years, it's difficult not to be anxious.
"As the trial date of June 4 approaches, I grow increasingly apprehensive and nervous about the fate of my wife," Iain Clayton wrote in a blog post for "Larry King Live."
Clayton said he writes and frequently sends care packages to his wife, which take up to three weeks to get to closed-off North Korea.
"I think it is this isolation that attracted them to the assignment in the first place," he wrote. "[It's] a trip that may end up with them indicted and tried, even though they were journalists simply covering a story."
CNN's Saeed Ahmed contributed to this report.