MOSCOW - Russia called on Friday for Washington to restart direct military-to-military cooperation to avert “unintended incidents” near Syria, at a time when U.S. officials say Moscow is building up forces to protect President Bashar al-Assad’s government.

The United States is leading a campaign of air strikes against Islamic State fighters in Syrian air space, and a greater Russian presence would raise the prospect of the Cold War superpower foes encountering each other on the battlefield.

Both Moscow and Washington say their enemy is Islamic State. But Russia supports the government of Assad, while the United States says his presence makes the situation worse.

In recent days, U.S. officials have described what they say is a buildup of Russian equipment and manpower.

Lebanese sources have told Reuters that at least some Russian troops were now engaged in combat operations in support of Assad’s government. Moscow has declined to comment on those reports.

At a news conference, Foreign Minister Sergei Lavrov said Russia was sending equipment to help Assad fight Islamic State. Russian servicemen were in Syria, he said, primarily to help service that equipment and teach Syrian soldiers how to use it.(Reuters)