Updated

A campaign led by a U.N. whistleblower that successfully changed U.S. law could cost the United Nations millions of dollars if it doesn't adhere to "best practices" to protect any U.N. employee who reports wrongdoing.

A law signed Jan. 17 by President Barack Obama contains a provision to automatically withhold 15 percent of U.S. funding for the U.N. or any of its agencies unless — or until — Secretary of State John Kerry certifies that its conduct toward whistleblowers meets five "best practices."

U.N. deputy spokesman Farhan Haq said Friday that the U.N. took note of the U.S. decision.

James Wasserstrom, who accused senior colleagues of retaliating after he alleged corruption in the U.N. peacekeeping mission in Kosovo, called the new provision "a major step in the right direction."