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By The Associated Press

VIENTIANE, Laos — A top aide of President Barack Obama said Tuesday he will meet with the wife of a missing Laotian activist, whose case has been repeatedly highlighted by human-rights groups as an example of authoritarian excesses of Laos' one-party Communist government.

Deputy National Security Adviser Ben Rhodes told reporters he will meet with Shui Meng Ng on Thursday while Obama is visiting Laos. The president arrived Monday to attend a regional summit.

Human-rights activists were hoping that Obama would speak about Ng's husband, Sombath Somphone, who was picked up apparently by security forces on Dec. 15, 2012. He has not been seen since.

Shui Meng Ng is seen at an Aug. 31 press conference in Bangkok about her missing husband, Sombath Somphone.RUNGROJ YONGRIT / EPA

Obama has not mentioned him so far in his public remarks, but Rhodes said that "we care very deeply about her case and her husband, and we believe she deserves to know what happened to her husband."

He said he also met Ng during a recent visit to Laos, and planned to stay in "regular contact" with her. Rhodes said the Laotian government has told the U.S. the same thing it tells Sombath's wife — that it's looking into his disappearance.

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"Oftentimes, they indicate that they do not know, and that there's an ongoing investigation," Rhodes said.

He said that typically, Obama addresses human-rights issues with foreign leaders more broadly, and lets his staff raise specific cases with their counterparts.

Sombath's disappearance was captured on a traffic video camera, in which he is seen being stopped at a police outpost in Vientiane and asked to step out of his Jeep, according to Amnesty International. Within a few minutes a man on a motorcycle arrives, drives away Sombath's vehicle, and a pickup truck takes Sombath away with armed people on a motorcycle leading the way. The passenger on the motorcycle fires a gunshot into the air, Amnesty International said.

The human-rights group said it believes the authorities are either directly responsible for his disappearance, or have simply failed to take steps to find out what happened to him.

"President Obama and world leaders gathering in Laos need to demand answers and accountability from their Lao government hosts on the case of disappeared NGO leader Sombath Somphone. The message has to be clear that the cover up has to end, Sombath needs to be found, and that no other outcome is acceptable," Phil Robertson, deputy director for Asia at Human Rights Watch, said Tuesday.

The U.S.-educated Sombath mostly worked in rural development, showing farmers creative ways to raise fish and make handicrafts. But he was also vocal about land deals that left thousands of villagers homeless without compensation, sparking rare political protests. He also had international connections.