Militants attacked a base with an explosive-laden vehicle and also targeted a convoy of rebel fighters.
Moscow had its S-400 missile system in range of the strike.
Syria's war, now in its seventh year, has killed hundreds of thousands and drawn local and international forces into a deadly contest for power.
Russian politicians have criticized the U.S. airstrike on the Syrian military.
The timing of the airstrikes may make for a day of uncomfortable meetings between the president and his Chinese counterpart.
Its payload, range and navigation benefits explained.
The president’s decision to strike a Syrian air base was in reaction to the suspected chemical attack in Khan Sheikhoun on Tuesday.
While Trump stopped short of calling on Assad to leave office, the comments were his strongest suggestion yet that the United States may be edging toward a stronger stance against Assad.
"American policy is based on creating chaos in different parts of the world and creating conflicts among states. This is not new," Syria's President Bashar al-Assad said.
Turkey's justice minister accused Bashar al-Assad of conducting a chemical weapons strike on Tuesday.
The killing took place in the al-Mayadin desert near Deir Ezzor city, according to a rights monitor.
Russia attempted to refute claims that the Assad regime was responsible for a suspected chemical attack that killed at least 72 people.
The international chemical weapons watchdog says it is gathering information about the attack that left dozens dead.
Secretary of State Rex Tillerson and U.S. Ambassador to the U.N. Nikki Haley said the U.S. was no longer interested in pursuing regime change in Syria.
The fall of the Syrian city could signal the end of ISIS’s state-building project.
Terrified residents fled to nearby hills.
A Kurdish and Arab coalition, backed by U.S. special forces, is waging the ground offensive against ISIS.