Border Patrol agents apprehended a group of 1,036 migrants attempting to cross the border near El Paso, Texas, early Wednesday morning, the largest group taken into custody to date.

The group included 63 unaccompanied children and 39 single adults, according to a senior official from Customs and Border Protection, which oversees the Border Patrol. Another 934 migrants indicated they were traveling with family members.

On a conference call with reporters, the official said a total of 180 large groups have attempted to cross the border this fiscal year, including 46 large groups comprising 9,200 migrants in the month of May. Most of the migrants are traveling from Guatemala, Honduras and El Salvador, the official said.

The group managed to breach a levy and some preliminary fencing before being taken into custody by Border Patrol agents.

President Trump posted surveillance video showing the migrants attempting to cross the border on Twitter.

The president declared a national emergency to address illegal immigration in February, after Congress refused to allocate enough funding to build his border wall. Mr. Trump vetoed a resolution attempting to block the national emergency.

About 99,000 migrants were apprehended between ports of entry along the border in April, according to the most recent CBP figures. The number of illegal crossings has spiked in recent months.

Mr. Trump unveiled an immigration plan earlier this month. The White House says the proposal would tighten family-based migration to focus on allowing nuclear families who migrate to the U.S., rather than extended family members.

However, the plan does not include key measures to secure bipartisan support, such as any protections for undocumented immigrants who arrived as children. It's unclear if a single Democrat has been consulted on the plan so far, and some Republicans have offered tepid responses to the proposal. Some Democrats have called the proposal dead on arrival.

Rob Legare contributed reporting.