She had planned to travel with Franklin Graham, the son of evangelical leader Billy Graham, and Fox News personality Greta Van Susteren, but other obligations prevented her from making the trip, Graham told The Washington Post.
The three had planned to be part of the July 9 independence ceremony when southern Sudan becomes the Republic of South Sudan, the sources said.
Van Susteren canceled her trip too, the Post said. Graham said he still plans to go.
But Palin said she did not cancel her One Nation Tour, after completing an East Coast bus excursion.
While not saying when the tour would continue or where she planned to go next, Palin said on Facebook, "the summer is long, and I'm looking forward to hitting the open road again."
She also said she was called to jury duty "and I look forward to doing my part just like every other Alaskan."