Burns, addressing the two-day ministerial conference of the OSCE in Ljubljana, said the United States is convinced the OSCE "is not broken" and that any reform must result in "strengthening, not weakening" the organization.
Earlier, Russian Foreign Minister Sergei Lavrov attacked the OSCE's Office for Democratic Institutions and Human Rights (ODIHR), which monitors elections, saying it had excessive autonomy and lacked clear guidelines to determine the nature of its work.
Burns rejected this criticism, saying: "The United States applauds the Office of Democratic Institutions and Human Rights, ODIHR. It is the gold standard worldwide in election-monitoring practices. ODIHR should be respected and it should be strengthened. It performs the crucial function of this organization, which is support for democracy and elections, to which every one of us, by the way, has agreed."
Lavrov's remarks coincided with a lukewarm report by the OSCE about yesterday's election in Kazakhstan, won by incumbent President Nursultan Nazarbaev.
On Uzbekistan, OSCE Chairman in Office Dimitrij Rupel said he would closely follow developments in connection with Uzbekistan's crackdown on an uprising in its eastern town of Andijon in May.
Also, Rupel cautiously praised for progress on unresolved conflicts in Georgia and Moldova. He said there was reason to believe Tbilisi and Moscow are taking steps toward implementing their agreement on the closure of Russian military bases in Georgia.
Rupel said that the OSCE was helping to build confidence among parties in the dispute over Georgia's breakaway region of South Ossetia.
As for Moldova, Rupel welcomed the resumption of negotiations on what he called a "peaceful and sustainable" resolution of the situation concerning the separatist Transdniester region.
(with news agencies)