A secure communications channel set up to prevent misunderstandings that might lead to nuclear war is likely to expand to handling new kinds of conflict — in cyberspace.

The Nuclear Risk Reduction Center, established in 1988 under President Ronald Reagan so that Washington and Moscow could alert each other to missile tests and space launches that could be mistaken as acts of aggression, would take a central role in an agreement nearing completion between U.S. and Russian negotiators.

Most key elements of the deal, which could be final in several weeks, are settled, said U.S. officials familiar with the talks.

The secure channel would be a milestone in the effort to ensure that misperceptions in cyberspace — where it is difficult to know who is behind a digital attack or even whether a computer disruption is the result of deliberate action — do not escalate to full hostilities, say U.S. officials and experts from both countries.

The talks reflect the increasing importance of cyber-activities as points of potential conflict between nations. The Obama administration has warned with growing urgency in recent months that a cyberattack could undermine systems that provide water, power or other critical services to Americans.

The agreement would be the first between the United States and another country seeking to lessen the danger of conflict in cyberspace, and it would include other measures to improve communication and transparency. It would be, officials and experts note, an initial step toward making cyberspace more stable.

“Both the U.S. and Russia are committed to tackling common cybersecurity threats while at the same time reducing the chances [that] a misunderstood incident could negatively affect our relationship,” White House spokeswoman Caitlin Hayden said.

Said Russian Embassy spokesman Yevgeniy Khorishko: “We feel that these confidence-building measures are important to preventing conflicts.”

The pact would be a positive development, in contrast to a generally downbeat U.S. assessment of Russian actions in cyberspace. An intelligence agency report last fall singled out Russia and China as aggressive perpetrators of cyber-espionage against economic targets. Russian organized-crime groups have been active for years in the cyber-theft of consumers’ credit card information and other data.

The agreement would not address those issues, or political differences in the extent to which governments can or should control speech on the Internet. At a conference in Germany this week, Russia pressed its campaign for a binding United Nations treaty on “information security” that would endorse the concept of a governmental role in controlling expression online. The United States opposes that effort.

Talks between the United States and the Chinese over cybersecurity are proceeding at a slower pace, officials say. American officials say the Chinese have not agreed with the U.S. position that the law of armed conflict, which requires the use of proportional force and the minimization of harm against civilians, applies to cyberspace.