Apprehensions of migrants at the U.S.-Mexico border by the U.S. government decreased dramatically in June, a sign that the months-long surge of Central American families journeying north is stalling.

Last month, U.S. authorities apprehended more than 94,000 migrants in between ports of entry along the southern border — a precipitous drop from May, when more than 132,000 people, including about 84,000 families and over 11,000 unaccompanied minors, were apprehended. The total number of apprehensions that month was a 13-year high.

The Department of Homeland Security (DHS), which oversees the border officials who apprehend migrants who cross into the country illegally, said there was a decrease in apprehensions of all groups in June. Border officials apprehended about 57,000 families, more than 7,000 unaccompanied children and approximately 30,000 single adults.

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In a call with reporters on Wednesday, a senior Customs and Border Protection (CBP) official said one of the positive signs for the agency is that officers have been encountering less large groups of migrants than in previous months. According to the official, CBP encountered 15 groups of more than 100 migrants in June and two so far in July, compared to about 45 in May.

Additionally, the official highlighted a sharp decrease in the number of unaccompanied children in the custody of CBP — which is supposed care for minors for no more than three days before transferring them to the Department of Health and Human Services (HHS). About 200 unaccompanied migrant children are in Border Patrol custody, compared to nearly 3,000 in late May and early June.

Officials nevertheless said the government's resources near the border are still stretched thin and continued to urge Congress to overhaul the nation's asylum system — which the administration and most Republicans see as a magnet for people in countries in Central America plagued by poverty, violence and political instability.

"We are still in a crisis," the CBP official on the Wednesday call said.

"We are past the breaking point and in a full-blown emergency. This situation should not be acceptable to any of us," DHS said in a statement on Tuesday.

Although apprehensions have in previous years decreased significantly in the summer months because of the sweltering heat in Central America and Mexico, DHS touted the agency's expansion of the controversial "Remain in Mexico" policy that forces certain asylum seekers to wait in Mexico while their cases are adjudicated in the U.S., as well as the Mexican government's efforts to bolster enforcement at the Mexico-Guatemala border. Both actions were provisions Mexico agreed to in a deal last month to ensure President Trump did not carry out his threat of imposing tariffs on Mexican goods.

"These initiatives are making an impact," DHS said in its statement.