Russia vows to solve U.S. reporter's murder

* Russia pledges to solve Klebnikov murder after Obama visit

* Formin says Russia treating probe with "great seriousness"

By Amie Ferris-Rotman

MOSCOW, July 9 (Reuters) - Russia on Thursday vowed to solve the murder of a U.S. investigative reporter, killed five years ago, after the United States used a visit by President Barack Obama to call on the Kremlin for justice to be done.

The murder of Paul Klebnikov on July 9, 2004 provoked international condemnation and underlined the dangers to journalists in Russia, ranked as one of the most risky places on earth for reporters.

"We will achieve our goal by finding those responsible for this crime," said Foreign Ministry spokesman Andrei Nesterenko, adding that the government is treating the investigation with "great seriousness".

U.S. Undersecretary of State William Burns on Tuesday urged Russia to redouble efforts to bring to justice Klebnikov's killers, who still remain at large.

Members of the Klebnikov family say they are frustrated by the lack of results in the investigation after repeatedly calling on President Dmitry Medvedev and Prime Minister Vladimir Putin to ensure justice is done.

"Frankly, I don't know if we will hear from the Kremlin," said Klebnikov's older brother, Peter, 52. "This is a deeply embarrassing case for Putin, I believe he would genuinely like to have the case solved."

"So far we are looking for deeds instead of words," said the New York-based environmental advocate who left his work as a journalist in Russia after his brother was murdered.

The two Chechen men suspected of murdering Klebnikov were acquitted in 2006.

U.S. watchdog the Committee to Protect Journalists (CPJ) says Russia is the third-deadliest country in the world for journalists after Iraq and Algeria.

"Paul Klebnikov loved Russia and sought through his journalism to hold the powerful to account," CPJ Executive Director Joel Simon said in a statement.

"It is deeply ironic, therefore, that five years after his murder those who perpetrated this terrible crime are still at large... Authorities in Russia should honor his legacy by bringing his murderers to justice." (Additional reporting by Conor Sweeney; Editing by Louise Ireland)