At the meeting Tuesday, Laos said the project should move forward, claiming the dam will comply with international standards.

But Laos' lower Mekong neighbors - Thailand, Cambodia and Vietnam - issued statements saying more information is needed about the dam's potential trans-boundary environmental impacts.

Vietnam issued the strongest statement, calling for a 10-year moratorium on new Mekong dams.

No agreement

The four lower Mekong countries failed to make a joint decision on the dam, but agreed to hold ministerial-level talks later this year.

Analysts say government statements and the decision to elevate MRC talks to the ministerial level raises the political stakes of the Xayaburi controversy.

Philip Hirsch is a professor of human ecology at the University of Sydney. He says that while the Mekong River Commission cannot stop Laos from building dams on the Mekong's main stream, the Mekong River Commission's protocols have allowed neighboring countries to put diplomatic pressure on Laos.

"If Laos was to go it alone [by building the Xayaburi dam] and not listen to the other countries, it would be doing so now against the express wishes of the other countries, and particularly against the express wishes of Vietnam, with which Laos has a very close relationship," noted Hirsch.

Face-off expected

Hirsch predicts there will be a face-off between ministers from Laos and neighboring Vietnam, which are both one-party communist states.