OSLO — The Pentagon is taking additional steps to ensure that U.S. and Russian battlefield commanders are able to directly communicate with one another after an airstrike on U.S. proxy forces near Deir al-Zour, Syria, that wounded several fighters Saturday, the United States’ highest-ranking military officer said.

Chairman of the Joint Chiefs of Staff, Marine Gen. Joseph F. Dunford Jr., told a small group of reporters Sunday that deconfliction between the United States and Russia “didn’t work” when Syrian and Russian aircraft bombed U.S.-backed Syrian fighters battling the Islamic State east of the Euphrates River.

Russia has denied participating in the strike, despite a U.S. statement Saturday that specifically indicated that Russian aircraft took part in the bombing.

During a Saturday night phone call with his Russian counterpart, Chief of the General Staff of Russia’s armed forces, Gen. Valery Geramisov, Dunford proposed that the countries’ respective battlefield commanders in charge of forces in Syria could use the deconfliction line established in 2015 to “address the fact that the enemy moves freely back and forth across the Euphrates River,” he said.

In the past, the deconfliction line was primarily staffed by a Russian and an American colonel responsible for alerting each other about their respective country’s air operations, but now with the commander of the U.S.-led coalition, Lt. Gen. Paul Funk, and Col. Gen. Sergei Surovikin in communication, the two countries are likely to have a better understanding of where their forces are arrayed.

“It couldn’t be more complex and crowded in that area,” Dunford said of the Euphrates River Valley. “Deconfliction is more difficult in that area than it was a few months ago.”

Traditionally the two countries have used the Euphrates as a dividing line, with Russian and Syrian government forces focused on attacking targets to the west while U.S.-backed forces and aircraft attacked to the east. In recent weeks, however, multiple offensive operations — launched by the United States and Russia — have nearly converged.

“We haven’t resolved all the issues,” Dunford cautioned, adding that conversations between the two countries are ongoing. After the errant strike, Secretary of State Rex Tillerson spoke to his Russian counterpart, Sergei Lavrov, Dunford said.