The U.S. and Russian militaries traded accusations during the weekend after Russian airstrikes against U.S.-backed rebels in Syria near the border with Iraq.

The Pentagon on Saturday said officials held a video conference with their Russian Defense Ministry counterparts to discuss Russian airstrikes on Thursday on rebels fighting Islamic State.

U.S. officials said the strikes endangered American personnel supporting local forces.

Moscow and Washington have been at loggerheads since the conflict in Syria began in 2011. Russia intervened last year with an air campaign in support of Syrian President Bashar al-Assad; while a tenuous cease-fire holds in some areas, Russia has continued to strike Islamic State, which isn’t covered by cessation of hostilities brokered by the U.S. and Russia.

The U.S. and Russia had been coordinating local cease-fires across parts of Syria where moderate opposition groups not linked to Islamic State and Nusra Front, another militant group, have signed on to truce efforts.

The Russian military on Sunday said conflicting information provided by Washington led to the strikes.

“Representatives of the Russian Defense Ministry explained that the points that were subjected to bombing were located more than 300 kilometers outside the territory [where a cease-fire is in operation],” Interfax quoted Russian Maj. Gen Igor Konashenkov as saying.

Russian Defense Minister Sergei Shoigu also met Mr. Assad, Moscow’s longtime client for arms and oil deals, on Saturday on orders from Russian President Vladimir Putin, Russian newswires reported.

Maj. Gen. Igor Konashenkov said the two had spoken about military cooperation between Russia and Syria against terrorist groups arrayed against Mr. Assad. Mr. Shoigu had spoken to Syria and Iran’s defense ministers in Tehran earlier this month.

Russia started its air campaign against Mr. Assad’s enemies late last year, but withdrew a large part of its forces in March after Mr. Putin declared that Moscow had met its basic objectives in Syria.

The faltering cease-fires and louder calls in Washington for direct involvement by the U.S. in Syria through targeted military strikes and regime change in Damascus has alarmed Moscow.

A Russian lawmaker on the parliamentary defense committee, Andrey Krasov, told Interfax that the meeting between Mr. Shiogu and Mr. Assad could point to a strengthening of Russian support for the Syrian president.

“I think what will follow will be a clarification of tasks, including those regarding our cooperation with the armed forces of the Syrian Arab Republic and to update the tasks of our military groupings in Syria,” Mr. Krasov said.

Source: www.wsj.com