US president Barack Obama toasted Thai premier Yingluck Shinawatra, held a historic discussion with Myanmar President Thein Sein and offered a warm farewell to Japanese Prime Minister Yoshihiko Noda earlier this week.

What he did not do during his three-day Asia trip – at least not according to the official White House photographic record – was share a single moment with Prime Minister Hun Sen.

In a 41-photo album of Obama’s trip posted on the White House website, the absence of Hun Sen is notable. There’s a shot of Obama with the Thai king, and four of him with Yingluck.

Thein Sein appears in one photo, and Myanmar pro-democracy icon Aung San Suu Kyi in three.

But of 13 photos taken in Phnom Penh – where Obama spent 25 hours attending ASEAN meetings, bilateral discussions and a dinner at which the Cambodian premier was present – not a single one features Hun Sen.

The one shot in which Hun Sen can be spotted in the distance makes no mention of him in the caption. It says only: “President Barack Obama delivers opening remarks at the US-ASEAN leaders meeting”, although the picture is, in fact, an image of Hun Sen delivering a remark.

“Of course, it’s deliberate. There couldn’t be any other explanation,” Carlyle Thayer, an emeritus professor of politics at the University of New South Wales, said. 

“It’s just a way of showing displeasure.”

Rights groups, opposition leaders and members of the US Congress spent much of the month before Obama’s visit urging him to either cancel it or press the Cambodian government hard on rights issues.

A public snub would strain protocol, but the exclusion of Hun Sen from the album sent the appropriate message to interested parties, Thayer said.

“It’s a nice way of putting Hun Sen down, and the congressmen would understand what he’s doing. It’s not a snub that’s public; he just didn’t put him in his photo book.”

To contact the reporter on this story: Abby Seiff at [email protected]