According to the newspaper, representatives of the US Central Intelligence Agency and Russia's Foreign Intelligence Service held a meeting in Moscow last week to discuss cooperation between the two countries on Syria.
Bild am Sonntag reported that Washington plans to render intelligence assistance to Moscow so as to support Russia's activity against ISIL militants in Syria.
The newspaper attributed Washington's move to the Islamic State's ever-increasing clout and the growing flow of refugees to Europe.
During a telephone conversation on Friday, Russian Defense Minister Sergei Shoigu and his US counterpart Ashton Carter agreed to continue to discuss the situation in Syria in the future.
Earlier that day, US Secretary of State John Kerry said that President Barack Obama sees the talks between the two countries' military as an important step.
Syria has been in a state of a civil war since 2011. Government forces have been fighting against opposition factions and numerous insurgent militant groups, including ISIL and the al-Nursa Front.
According to UN figures, more than 220,000 people have been killed in Syria since the conflict began, with the number of Syrian refugees abroad exceeding 4 million people.
