The US military has sent additional troops and equipment into northeast Syria.

US Central Command said in a statement that it “has deployed Sentinel radar, increased the frequency of US fighter patrols over US forces, and deployed Bradley fighting vehicles to augment US forces”.

A US official said up to six armored vehicles, transferred from a base in Kuwait, and 100 personnel were being moved.

Central Command gave no specific reason for the deployment, but tensions have risen with Russian personnel in the area, which is controlled by the US-backed Syrian Democratic Forces after the Islamic State was expelled between 2017 and 2019.

Last month seven US troops were injured in a collision between American and Russian armored vehicles. Each side blamed the other for the breaking of a “deconfliction arrangement”.

See UPDATED: 7 US Troops Injured in Clash With Russians in Northeast Syria

Russia and the Assad regime have also put pressure on the Kurdish authority’s control of oilfields. Most of Syria’s oil is in the northeast, and the regime is facing critical shortages of fuel.

Central Command spokesman Capt. Bill Urban said the deployment will “help ensure the safety and security of coalition forces….[The US] does not seek conflict with any other nation in Syria, but will defend coalition forces if necessary.”

The military official was more direct: “[This is] a clear signal to Russia to adhere to mutual de-confliction processes and for Russia and other parties to avoid unprofessional, unsafe and provocative actions in northeast Syria.”

Donald Trump ordered the full withdrawal of US troops, backing the Kurdish SDF since autumn 2015, in December 2018 and again in October 2019. The Pentagon pushed back to retain half the American forces — about 1,000 personnel — but the Bradley fighting vehicles were pulled out.

About 500 personnel are alongside the Syrian Democratic Forces, with the others positioned at the Tanf base in eastern Syria near the Iraq border.