The “Remain in Mexico” policy took effect in January 2019 in San Diego and sent back nearly 60,000 people to wait for hearings.

The tunnel measured over 4,000 feet long and included a rail system, electricity, ventilation and two elevators.

Customs and Border Protection officials said in a statement that the barricades were erected for safety reasons.

The U.S. president wants more than 700 kilometres of fencing along the nearly 3,218-kilometre border completed by the end of 2020.

The spicy peppers failed to distract sniffer dogs from detecting the marijuana concealed inside.

In July, there were 82,049 people encountered by U.S. Customs and Border Protection, down 21 per cent from June when there were 104,344 people and down 43 per cent from May. The number of families and minors crossing the border also dropped.

Immigrants can get permits to work legally in the United States once their asylum applications are pending before a judge for six months, which many with fast-tracked cases won’t get to do, lawyers said.

The seesaws are meant to show that actions on one side of a border have consequences on the other — and they don't have to be bad.

Democrats accuse Trump of tolerating badly overcrowded and putrid holding facilities in a purposeful effort to discourage future immigrants.

U.S. Border Patrol Chief Carla Provost said the posts are "completely inappropriate and contrary to the honour and integrity I see — and expect — from our agents."