Foreign governments are worse than the United States in hiding information from the public. For instance, even in an open, democratic society such as Australia, the government tried to hide information that the Great Barrier Reef is dying. Many other countries have much more oppressive governments that are run by dictators.
I don't think that foreign governments cover up more issues than the US because though the US government claims to be transparent, plenty of sketchy situations get labeled as classified information and swept under the rug under the guise of security. Also, our media tends to manipulate events and issues, and some conglomerates are biased for political reasons.
All governments are particularly bad about hiding information. Sometimes they do it for altruistic reasons, which may be the case with the Great Barrier Reefs. They could be dying because so many tourists visit them. But other times governments are simply trying to save face or to sway public opinion.
Many scientists are now saying it is almost too late to save it. Strong and immediate action is required to alleviate water pollution and stop the underlying cause: climate change. Australians are being wooed by politicians for an upcoming federal election, most of whom support policies that will guarantee the reef’s destruction.