US officials, lawmakers and technology leaders voiced firm opposition Thursday to efforts to bring the Internet under UN control, saying it could hurt free expression and commerce.

At a congressional hearing, the comments were united in opposition to place the Internet under the jurisdiction of the International Telecommunications Union, a United Nations agency which governs telecom systems.

"There's a strong, bipartisan consensus within the (US) administration and Congress that we must resist efforts from some countries to impose a top-down governance of the Internet," Representative Henry Waxman told the hearing.

Congresswoman Doris Matsui added that "any international authority over the Internet is troublesome, particularly if that effort is being led by countries where censorship is the norm."

A top State Department official, in prepared remarks, reaffirmed the opposition of the Obama administration to UN governance of the Internet.

"In all bilateral encounters and multilateral meetings, the United States consistently opposes the extension of intergovernmental controls over the Internet," said Philip Verveer, deputy assistant secretary of state and coordinator for IT policy, saying this would lead to "very bad outcomes."

"It inevitably would diminish the dynamism of the Internet," he said.

Verveer told lawmakers that UN control would possibly "aid in censorship and repression" in some countries.

The comments come ahead of a meeting in December of the ITU where some nations will be pressing for the agency to formally govern the Internet.

Some nations, including Russia and China, say the Internet is still controlled by the United States and that a UN effort would give a greater voice to the developing world.

But many in the US fear a UN-governed Internet would give authoritarian nations the power to throttle free speech, and allow others to impose tariff or other restrictions.

The Internet is currently a loosely governed network, with an address system managed by a nonprofit association that was recently opened to include nongovernment groups and other organizations around the world.

A staff memo to the House Energy and Commerce Committee, which called Thursday's hearing, said handing over the Internet to the UN "could jeopardize not only its vibrancy, but also the economic and social benefits it brings to the world."

Vint Cerf, a computer scientist often called the "father of the Internet," who is now Google's "chief Internet evangelist," also expressed concern about the proposal.

"The Internet's success has generated a worrying desire by some countries' governments to create new international rules that would jeopardize the network's innovative evolution and its multi-faceted success," he said in prepared remarks.

A move to UN control, he said, "holds profound -- and I believe potentially hazardous -- implications for the future of the Internet and all of its users. If all of us do not pay attention to what is going on, users worldwide will be at risk of losing the open and free Internet that has brought so much to so many."

Sally Shipman Wentworth of the Internet Society, an advisory panel, said the current system works well, and that UN governance "could lead to a more fragmented, less interoperable global network."

US Federal Communications Commissioner Robert McDowell said the proposals represent threats to the Internet.

"For many years now, scores of countries led by China, Russia, Iran, Saudi Arabia, and many others, have pushed for, as then-Russian Prime Minister Vladimir Putin said almost a year ago, 'international control of the Internet' through the ITU," he told the panel.

"Such a scenario would be devastating to global economic activity, but it would hurt the developing world the most."