(CNN) Customs and Border Protection continued to quickly remove migrants arriving at the southern border in May, following the Trump administration's new rapid expulsion policy implemented in the wake of the coronavirus pandemic.
Of the 21,475 people arrested on the southern border last month, 19,707 were expelled from the US under a public health order put in place in March, according to data released Friday.
The overall number of people arriving at the southern border rose from the previous month. Border arrests -- a measure of illegal crossings -- increased from about 16,000 in April to more than 21,000 in May.
However, the number of migrants arriving at the southern border is down drastically from last year. Last May, 132,856 people were apprehended at the peak of the 2019 migrant border crisis, which stemmed largely from families fleeing the Northern Triangle countries of Guatemala, Honduras and El Salvador.
Demographics have also shifted since last year. Most people currently encountered illegally crossing the border are single adult men from Mexico. In May, 82% of CBP's enforcement encounters were with Mexican nationals, with 13% from the Northern Triangle.
In May 2019, only 16% of migrants were from Mexico and 72% were from the Northern Triangle, according to the agency.
Last month, the administration extended travel restrictions and stringent border control measures related to the coronavirus pandemic.
Even as the United States moves toward reopening, the federal government is not ready to ease measures put in place in March that largely sealed off the US to stem the spread of Covid-19. The strict rules also have the effect of continuing to curb immigration to the US.
"These policies will exist at our borders until the further introduction of Covid-19 into the United States has ceased to be a serious danger to the public health," said acting CBP Commissioner Mark Morgan in a statement at the time. "Imagine the disaster at our borders if there were a sudden migrant surge from Mexico and other counties," he added in part.
Earlier this week, CNN reported that the Trump administration is preparing to roll out another set of restrictions on legal immigration, citing the impact of the coronavirus pandemic, even as it argues for the reopening of the US economy, according to sources familiar with the deliberations.
The administration has pressed forward with a series of immigration measures that, prior to coronavirus, had struggled to break through. Among those changes is the closure of the southern border to migrants, including those seeking asylum, unless certain conditions are met.
A slate of visas, which allow immigrants to temporarily work in the US, are under consideration to be suspended for a period of time, including L-1 visas for intracompany transfers, H-1Bs for workers in specialty occupations, H-2Bs for temporary non-agricultural workers and J-1 visas for exchange visitors, according to three sources familiar with plans.