When the Baptist World Alliance held its global conference in Hawaii earlier in August, it was missing about 1000 attendees from around the world.
In June, the inaugural meeting of the World Communion of Reformed Churches in Grand Rapids, in the US state of Michigan, was missing 74, and the Seventh-day Adventists' general conference in Atlanta was missing about 200, Religion News Service reports.
The three church groups said foreign delegates' visas were denied by US officials, meaning some nations lacked representation at the global assemblies which occur only once every several years.
The Rev Susan Davies of the United Church of Christ said she was "outraged" at the WCRC visa denials. Organisers of the gathering erected a banner to mark their absence.
''I was deeply saddened" by the visa problems, said the Rev Clifton Kirkpatrick, the former president of the World Alliance of Reformed Churches, which merged with another group in Grand Rapids to form the World Communion of Reformed Churches.
''I don't think you hear of government events or corporate events that have this percentage of people denied visas."
A lot of it had to do with money, he believes, saying "the criteria (for securing visas) are so skewed to the financial status of people involved."
Church officials say they fully complied with State Department rules on international visas for visiting delegates, particularly providing evidence that visitors would return to their country of origin once the meetings ended.
''We registered our session with the US State Department, and they put it on their internal intranet site," said Rosa Banks, associate secretary of the Adventists' General Conference. "And we updated it on a weekly basis when we got into the process."
Like the Reformed gathering, Adventists said they found many of the rejected visas came from poverty-stricken areas of the world.
''The countries where we had the most problems were in West Africa, particularly Nigeria, and districts in India," said Banks. "We have to assure that our delegates are going to return."
Acknowledgements to ENI www.eni.ch