The troops were flown by helicopter to the base at At Tanf — a small town near the borders of Syria, Iraq and Jordan. The base is used by U.S. special forces to train Syrian fighters who are confronting Islamic State militants.
Moscow has sent multiple messages to the U.S. in recent days, warning that it and Syrian regime units were planning an attack on what they refer to as “terrorists” near Tanf, U.S. officials said.
The Russian threats may be a way of testing U.S. resolve to keep troops in Syria now that President Bashar Assad’s forces, backed by Russian troops and warplanes, have succeeded in defeating rebels everywhere except Idlib province and areas of eastern Syria controlled by the U.S. and its allies.
U.S. military officials bluntly warned Russian and Syria not to go forward with an attack within a 35-mile-wide security zone that the U.S. maintains around Tanf, a key strategic outpost.