In this file photo dated Dec. 3, 2012, participants listen to the speech of Hamdoun Toure, Secretary General of International Telecommunication Union, ITU, seen on screens, at the World Conference on International Telecommunication in Dubai, United Arab Emirates. (Kamran Jebreili/AP)

The Obama administration announced Thursday that it will refuse to sign a U.N. treaty under consideration at a major global telecommunications conference because of provisions that it says would give a U.N. stamp of approval to state censorship and regulation of the Internet and private networks.

“The United States has announced today that it cannot sign” the treaty’s provisions “in their current form,” said Terry Kramer, the U.S. ambassador to the World Conference on International Telecommunications, on Thursday as the 12-day conference draws to a close this week. Representatives of several other of the world’s largest economies also spoke out against the treaty, causing it to collapse for all practical purposes.

The treaty has been debated at a conference in Dubai, United Arab Emirates, sponsored by the International Telecommunication Union, a United Nations organization focused mostly on setting technical standards for global phone calls.

ITU officials had said earlier that the meeting, the agency’s first major review of a telecommunications agenda since 1988, was not going to be a referendum on Internet freedom.

But late Wednesday night, according to administration officials, the conference chairman, Mohamed Nasser al-Ghanim, director general of the Telecommunications Regulation Authority of the UAE, inserted a resolution in the treaty that broke open the deep divisions between the countries on Internet regulation.

“The United States has consistently believed . . . that the scope of the treaty does not extend to Internet governance or content,” Kramer said in a news conference call. “Other administrations have made it clear that they believe the treaty should be extended to cover those issues so we cannot be a part of that consensus.”

But ITU Secretary General Hamadoun I. Touré rejected the United States’ characterization of the treaty. “The new . . . treaty does NOT cover content issues and explicitly states in the first article that content-related issues are not covered by the treaty,” he said in a statement Thursday.

“History will show that this conference has achieved something extremely important. It has succeeded in bringing unprecedented public attention to the different and important perspectives that govern global communications,” he said.

A vote on the treaty is taking place Friday, and Kramer said it is unclear how many nations will abstain. “If there’s enough consensus to proceed, there’ll be an actual signing ceremony,” he said, with the countries that agree with the provisions signing the treaty.

But the document does not take effect until January 2015, and he said it is more “normative” than legally binding. In practical terms, U.S. officials said, the rules cannot be effectively carried out without international consensus because of the global nature of the Internet, which turns on services provided by governments and commercial providers.

Still, the divergence of perspectives is troubling, officials said. “It is clear that the world community is at a crossroads in its collective view of the Internet,” Kramer said.

The U.S. delegation is concerned with measures that would give governments new authority to regulate spam on their Internet networks. U.S. officials fear that states could use that provision to monitor and silence dissidents and others under the auspices of U.N. approval. “One man’s spam is another man’s political speech,” said one administration official, who spoke on the condition of anonymity, lacking the authority to discuss the matter on the record.

The Americans also opposed expanding the definition of what the treaty covers from public telecommunications networks to any network, public or private, including Internet service providers and government systems. They also were concerned about efforts to include network security in the treaty.

The provisions that the United States finds objectionable had been raised last week by Russia, China, the UAE and other countries. They were opposed by the United States and most European countries.

The United States sent more than 100 government officials, academics, civil society members and industry officials to the conference. The ITU says it traditionally operates by consensus.

Kramer noted that countries have sovereign rights to do what they want within their borders, “but obviously we don’t want to have agreements globally that set a tone.” So, he said, in the coming months and years, “we’re going to have to continue to advocate the importance of the global nature of the Internet.”

Craig Timberg also contributed to this report.