That position drew praise from lawmakers and activists back home.
House Cybersecurity Caucus co-chairs Jim Langevin and Michael McCaul said the treaty, if implemented, "would result in a significant setback for anyone who believes free expression is a universal right".
Google, another critic of the conference, said that many governments taking part in Dubai proved they wanted increased censorship.
"What is clear from the ITU meeting in Dubai is that many governments want to increase regulation and censorship of the internet," a Google spokesperson said in a statement.
"We stand with the countries who refuse to sign this treaty and also with the millions of voices who have joined us to support a free and open web."
Kieren McCarthy, general manager of the Global Internet Business Coalition, called the outcome in Dubai "a humiliating failure" for the UN agency.
"The collapse will come as a severe embarrassment to the ITU," McCarthy said in a blog post. "Efforts to bring its core telecom regulations into the internet era had exposed the organisation to modern realities that it was incapable of dealing with."
Milton Mueller, an Internet governance specialist at Syracuse University, said it's not clear if the new language is a threat to a free internet.
"While I didn't like the resolution nor did most internet rights advocates, I doubt if its passage would in itself be able to do much harm," he said.
But Mueller said the diplomatic efforts were complicated by concerns in some countries -- mainly with "bad" human rights records - who object to US sanctions that can cut off access to certain internet services such as those from Google.
"Weird and ironic, in that it is the pro-human rights nations that are using denial of access to internet services as a form of policy leverage, and the anti-human rights nations that are claiming a universal right of internet access," Mueller said.
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