Foreign Minister Sergei Lavrov warned the United States on Friday that a decision to extend a trade ban on state arms trader Rosoboronexport threatened to undermine fraught ties between Moscow and Washington.

A senior U.S. official, however, said the sanctions merely reflected Washington's concerns about arming Iran.

The sanctions issued by the U.S. State Department forbid U.S. government agencies from dealing with Rosoboronexport and 12 other companies in five countries because of their weapons shipments to Iran, which Washington suspects of building a nuclear bomb.

Lavrov accused Washington of breaking international law by imposing domestic policies on sovereign countries. "This is absolutely incompatible with the new realities in the current world structure," he said at a news conference after talks with Luxembourg's foreign minister, Jean Asselborn.

"We will take this into account in our relations with the …