The U.S. government is moving forward with plans to use military funds to build border barriers in Arizona and New Mexico.

The Department of Homeland Security issued waivers to environmental laws last week to build and replace 46 miles (74 kilometers) of barriers near Columbus, New Mexico, and 11 miles (17 kilometers) near Yuma, Arizona.

The barriers are being funded by the Department of Defense following President Donald Trump's emergency declaration in February.

Last month, the federal government announced it had awarded contracts of nearly $1 billion to replace short barriers with tall fences in those areas.

The southern border has seen an influx of immigrants over the last several months and officials say they expect to make up to a million arrests by the end of the year.