(For full coverage of reporters' release, click on [nNORKOR])
* Bill Clinton brings two journalists back to L.A.
* Obama says N.Korea must give up nuclear weapons program
* U.S. insists there's no link to nuclear talks
* McCain says Pyongyang using Clinton for propaganda (Updates with McCain quote, edits)
LOS ANGELES, Aug 5 (Reuters) - Two American journalists freed by North Korea tearfully reunited with their families in the United States on Wednesday while Washington tried to play down talk of a breakthrough with Pyongyang.
Laura Ling, 32, and Euna Lee, 36, reporters for an American cable television venture arrived at Burbank airport near Los Angles aboard a private jet with former President Bill Clinton, who secured their release after meeting over dinner with North Korea's reclusive and ailing leader, Kim Jong-il.
President Barack Obama said he was "extraordinarily relieved" at the women's return but insisted the way for North Korea to improve relations with the United States was to give up nuclear weapons and stop its belligerent behavior.
Clinton's dramatic visit was the first high-level U.S. contact with North Korea in nearly a decade.
Despite the mission's success, the drama underlined the fine line Washington treads to avoid rewarding Pyongyang after repeated military provocations while trying to coax it into giving up its ambitions of becoming a nuclear-weapons power.
Critics of North Korea, including Republican Senator John McCain, accused Kim of using Clinton's visit to enhance his position amid doubts about his health.
They urged the Obama administration not to sidestep six-nation negotiations by engaging in direct bilateral talks with North Korea on ending its nuclear weapons program, a move that worries U.S. allies South Korea and Japan.
North Korea quit the on-and-off negotiations last year and has since insisted it will only talk with Washington.
Ling thrust her arms in the air as the two beaming women descended from the plane to an emotional reunion with their families in an airport hangar. Lee hugged Hana, the 4-year-old daughter she had not seen for five months.
Ling said they both feared they could be taken to a hard labor camp when they were led instead on Tuesday to a location where Clinton was waiting for them.
"We knew instantly in our hearts that the nightmare of our lives was finally coming to an end. Now we stand here home and free," she told reporters.
The two journalists, who work for Current TV, co-founded by Clinton's vice president, Al Gore, were arrested on March 17 for illegally crossing into North Korea from China and had been reporting on the trafficking of women. They were both sentenced to 12 years of hard labor in June.
Clinton did not speak on arrival, but said in a statement that the women's families, Gore and the White House had asked him to undertake the humanitarian mission to Pyongyang.
The former president, who tried unsuccessfully to halt North Korea's nuclear arms program in the 1990s, spoke briefly with Obama by telephone and will brief national security officials on his meeting with Kim, the White House said.
North Korea painted the meeting between Clinton and Kim as high-level talks the North Korean leader will certainly use to boost his image at home. [ID:[nSP535186]
In North Korean media photos, Kim was smiling and looked in reasonable health after speculation he was seriously ill. Some reports have said Kim may have suffered a stroke last year and is grooming his youngest son to succeed him.
"I think it'll be very interesting," said McCain. "He's the first Westerner to see Kim since his reported stroke and other problems. I think former President Clinton will have some interesting information."
North Korea's KCNA news agency said Kim issued a special pardon to the U.S. journalists enabling them to leave. It also reported that Clinton and Kim agreed their two countries should settle "pending issues" between them through dialogue.
The Obama administration insisted it had not offered any sweeteners to North Korea in its nuclear standoff with the West in return for its release of the journalists, although a senior U.S. official said Clinton did talk to North Korea's leadership about the "positive things that could flow" from freeing them.
"We were very clear that this was a humanitarian mission. President Clinton was going on behalf of the families," Obama said in an interview with MSNBC television.
"We have said to the North Koreans there's a path for improved relations and it involves them no longer developing nuclear weapons, not engaging in provocative behavior."
Clinton's wife, Secretary of State Hillary Clinton, said in Nairobi there was no connection between efforts to free the journalists and the thorny nuclear issue. [ID:nL5276240]
Critics of her husband's mission said Pyongyang had clearly linked the journalists' case to the nuclear issue by sending its top negotiator, Kim Kye Gwan, to greet Clinton at the airport.
Analysts speculated that Clinton's meeting with Kim could open the way to direct nuclear disarmament talks between Washington and Pyongyang. [ID:nN04166831] [ID:nSP529443]
Financial markets in Tokyo and Seoul largely ignored the women's release, although some South Korean traders said it added a more positive atmosphere to what had been a string of negative reports over the North in recent months.
North Korea fired a barrage of short-range missiles in launch tests in May and exploded a nuclear device on May 25, resulting in tougher U.N. sanctions that it has ignored. (Additional reporting by Steve Holland, Paul Eckert, Ross Colvin and Matt Spetalnick in Washington; Jack Kim in Seoul, Lucy Hornby in Beijing, Chisa Fujioka in Tokyo, Sue Pleming in Nairobi; Writing by Anthony Boadle and Christopher Wilson; Editing by David Storey and Peter Cooney)