President Donald Trump is to send “a surge” of federal security forces to US cities in a crackdown on crime.
Chicago and two other Democratic-run cities are being targeted in the Republican president’s move, amid a spike in violence.
But federal deployments in Portland, Oregon, have proved controversial. Local officials say they have raised tensions amid ongoing protests.
Law and order has become a key plank of Mr Trump’s re-election bid in November.
Since the death on 25 May of an unarmed black man, George Floyd, in police custody in Minneapolis, Minnesota, there have been protests – sometimes descending into civil disorder – in scores of US cities.
Meanwhile, gun violence has spiked in metropolitan areas including New York City, Philadelphia, Los Angeles, Chicago and Milwaukee.
In Portland, which has seen more than 50 days of protests, Mayor Ted Wheeler was tear-gassed by federal agents while attending the city’s protest on Wednesday night.
Speaking to a New York Times reporter, he said the tear-gassing was “an egregious overreaction” by federal officers, and that he “saw nothing that provoked this response”.