The policy shift marks a "great accomplishment," said Bob Boorstin, director of policy communications for the search-engine giant.
During a speech at a conference in Geneva, Boorstin said Google could now offer citizens in those countries access to such services as Google Earth, its mapping software; Google Talk, its instant-messaging tool; and Picassa, its photo-sharing site.
The Treasury Department announced its change in Web communications export rules early Monday. It stressed that the availability of chat, blogging, photo-sharing and social-networking tools in Iran, Sudan and Cuba would help human-rights activists there advance democratic reforms.
"Today’s actions will enable Iranian, Sudanese and Cuban citizens to exercise their most basic rights,” Deputy Treasury Secretary Neal Wolin explained in a statement on Monday.
The move arrives as an increasing number of states — from China to Iran — have started cutting access or otherwise censoring Web communication in an attempt to silence dissidents or to prevent anti-government protests.
The State Department has repeatedly argued against such abuses of Internet freedom, and Secretary of State Hillary Rodham Clinton has routinely stressed the United States plans to lead the global charge for unfettered Web access.
But neither her agency nor other federal officials had taken much formal, substantive action to encourage free Web communication in authoritarian states until Monday — even despite increasing congressional pressure on the issue.