American journalists Laura Ling and Euna Lee have been held by the North Korean government since March 17, accused of illegally crossing into the country while on a reporting trip in China for Current TV.
The families of the two detained journalists have so far remained silent, on the advice of the State Department, which says it has been working diligently behind the scenes to get the women released.
But with a June 4 trial date for Ling and Lee in North Korea approaching, ABC News "Nightline" contributor Lisa Ling -- sister of Laura Ling -- says she received a phone call that changed her mind about going public with her sister's story.
"At 11:00 at night my phone rang, and not having heard her voice for almost three months now, I picked up the phone and she said, 'Hi, Li. It's me.' And I mean I was just astounded.
"And she said, 'I'm still here. I need your help,'" Ling recalled. "And that phone call lasted about four minutes, during which she essentially said look, the only thing that could help us is if our two countries communicate.
"She's really scared," Lisa said of her younger sister, who is 32. "I mean she's terrified."
Lisa said her sister told her that she and Lee were being treated fairly but that "the only thing that is going to help us is if our two countries can talk."
So Lisa is trying to relay her sister's message publicly, urging direct communication between the United States and North Korea even as tensions between the two countries are ratcheting up, with North Korea's recent missile and underground nuclear tests.
"Given everything that's happening in the news -- I mean we're talking about what seems to be a full-blown nuclear standoff, and my little sister and Euna Lee are seemingly in the midst of it, and we just felt like it was really time to try and urge our two countries to communicate on our issue and to separate it," Lisa said. "Our issue is a humanitarian issue, and we hope that our two countries that don't have a diplomatic relationship can come together to resolve this and try and get the girls released."
"We both travel all over the world and I don't think that there has been a single day that we haven't spoken. I mean, I can be in the middle of the Himalayas and she can be in the Ukraine, and we'll somehow manage to get a phone call out.
"And so to not have been able to talk to her in months has been so hard."
Lisa said she's been keeping a vigil with her parents and Laura's husband of five years, Iain Clayton.
Since the arrest, Lisa has spent almost every weekend with Euna Lee's husband, Michael Saldate, and the couple's 4-year-old daughter.
"Euna has this beautiful 4-year-old daughter, Hana," Ling said. "And when she walked into the door of our home our hearts just broke because her husband Michael has all of a sudden kind of become a single parent instantly."
Lisa said Lee's prolonged absence is beginning to affect Hana. "She drew a picture the other day that just had her dad and her in it. Her mom wasn't in the picture, and he said that that's the first time that that's ever happened."
Ling and Lee are scheduled to go on trial in North Korea Thursday. They've been charged with hostile acts. If found guilty, they could be sentenced to up to 10 years in jail.