Iranian-backed forces have continued to attack US troops in Syria and Iraq even after US forces conducted a retaliatory strike on a weapons storage facility in eastern Syria.

The US military struck the facility used by Iran's Islamic Revolutionary Guard Corps and affiliated groups on Wednesday. It said the strike was for self-defense against repeated attacks on US military personnel in the region.

The US Defense Department's Deputy Press Secretary Sabrina Singh told a news conference on Thursday that the Pentagon believes the strike was successful and the building was now "pretty much non-usable."

But she went on to say that there had been four additional attacks since then on US troops in Syria and Iraq.

Singh said US and coalition forces had been attacked at least 46 times between October 17 and November 9, and that 56 people had been injured.

Also on Thursday, a reporter asked President Joe Biden whether the retaliatory strikes are working. Biden said, "They're working in the sense that we're hitting the targets."

On October 26, US forces struck two facilities in eastern Syria used by the Revolutionary Guard Corps and affiliated groups.

But attacks on US troops in the region continue amid the fighting between Israel and the Islamic group Hamas in the Gaza Strip.