The US Army Corps of Engineers has approved construction of two fences along the U.S. southern border that will make it harder for people and animals to cross the border.
Fence construction on the Rio Grande, a 3,000-mile (4,400-km) stretch of the Rio Americano that connects Mexico and Texas, has been underway since at least 2015.
The Corps has been building the fences since January 2020, and the latest phase is expected to be completed by March 2019.
The first phase of the fencing was completed in February 2019, and construction began in June 2020.
The Corps says the second phase will take longer to complete, but it said in a statement it will not delay construction because of environmental concerns.
During the time between when the first phase was completed and when the second was finished, the Corps completed fencing along the Rio Amistad, a section of the border that connects Guatemala to Mexico, and along the southern tip of the Tijuana river, according to the Corps.
Fence completion on the Tampico section of border is expected in April 2020, according the Corps, and completion of the southern border fence is expected by December 2020.
President Donald Trump has said he wants the border wall to be built to keep out drugs and violence, which has caused some apprehension.
The border is the largest barrier to trade in the world, and in 2018, it accounted for about a third of U.N. trade in goods, the agency said.
Border control officials say the wall has stopped thousands of drug-trafficking cases and more than 8,000 deaths.