Updated at 6:23 p.m. EST

WASHINGTON — The United States will not adopt the European Union’s proposed “code of conduct” for space activity as currently drafted on the grounds that it is too restrictive, according to U.S. government officials.

“It’s been clear from the very beginning that we’re not going along with the code of conduct,” Ellen Tauscher, undersecretary of state for arms control and international security, said during a Jan. 12 breakfast with reporters here.

Asked why the U.S. government would not sign the document, Tauscher said, “It’s too restrictive.”

However, another U.S. government official said the draft code is not being rejected outright and that it could serve as basis for a future document. “The U.S. has been consulting with the EU on its proposed international code of conduct,” this source said. “The draft code developed by the EU could be a good starting point for future discussions on an international code of conduct.”

The EU has been working the voluntary code of conduct for several years. The document lays out rules of the road for operating satellites and other space vehicles as space becomes increasingly congested, the idea being to minimize the chances of collisions or misunderstandings that could escalate.

The code also focuses on space debris mitigation, an area that began getting greater public attention in 2007 after China destroyed one of its own orbiting satellites with a ground-launched missile.

“We made it very definitive that we were not going to go ahead with the European code of conduct; what we haven’t announced is what we’re going to do, but we will be doing that soon,” Tauscher said.

Her remarks contrasted with previous U.S. government statements regarding the code, which have been relatively circumspect. In April, for example, Ambassador Greg Schulte, U.S. deputy assistant secretary of defense for space policy, described the draft code as a “positive approach” but stressed that the U.S. government had not yet decided whether to sign the document.

Some U.S. lawmakers have raised concerns that signing the nonbinding agreement would tie the U.S. military’s hands in space. “We’ve advanced further technologically in development and actual deployment of these systems than anyone else, and agreements [and] codes of conduct tend to … constrain our military,” Sen. Jeff Sessions (R-Ala.) said during a hearing on the subject in May.

The Pentagon has concerns with the European strategy for space traffic management, but there are also “ways to deal with it,” according to Michael Krepon, co-founder of the Stimson Center, a think tank here. The U.S. Defense Department did a lengthy assessment of the code of conduct and reviewed particular provisions within the document that “would make sense for our national security.”

“If the satellite is stealthy, or we want it to be stealthy, how does that fit into a traffic management system?” he said. “Now you argue … major spacefaring nations can figure out the orbital characteristics of objects in space, but it you want to move an object in space do you provide advance notice of this or how do you handle that?”

In 2004, the Stimson Center published a draft code of conduct for space, which is similar to the document pushed by the European Union.

“I think the problematic piece that the administration was struggling with was that it was made in Europe and that the really important space-faring nation felt no ownership of it,” he said.

Russia, China, India and Brazil have all distanced themselves from the document, Krepon said. At the same time, Canada and Japan have endorsed the document.

“I think the conundrum that the administration is facing is how to bring in major space-faring nations that have kept their distance from the EU’s handiwork,” he said.

U.S. Air Force Lt. Col. April Cunningham, a spokeswoman for the Defense Department, said the Pentagon supports an international code of conduct for space activities.