As U.S. Catholic leaders urged compassion and a solution to a possible collision over migration at the border that respects human dignity, Pentagon officials said today that the number of military troops deployed to the southern border could be in the thousands, not hundreds. The Wall Street Journal reports that its Pentagon sources now say the deployment could be as large as 5,000 troops, mainly military police and engineers—significantly higher than the 800 troops that the Trump administration initially suggested were on their way to the border.

But the U.S. Conference of Catholic Bishops pushed back against rising anti-migrant rhetoric in a joint statement the same day issued with Catholic Charities USA and Catholic Relief Services. “As Catholic agencies assisting poor and vulnerable migrants in the United States and around the world, we are deeply saddened by the violence, injustice, and deteriorating economic conditions forcing many people to flee their homes in Central America,” wrote Bishop Joe S. Vásquez of Austin, chairman of the U.S. bishops’ migration committee, in a statement also signed by Sean Callahan, president and C.E.O. of Catholic Relief Services, and Donna Markham, O.P. PhD., president and C.E.O. of Catholic Charities USA.

“While nations have the right to protect their borders, this right comes with responsibilities: governments must enforce laws proportionately, treat all people humanely, and provide due process,” they said.

The U.S. church leaders added that “seeking asylum is not a crime.”

“As Catholic agencies assisting poor and vulnerable migrants…we are deeply saddened by the violence, injustice, and deteriorating economic conditions forcing many people to flee their homes in Central America.”

Troops deployed to the border will perform a wide variety of functions, such as transporting supplies for the Border Patrol, but it is not expected that they will engage directly with migrants seeking to cross the border from Mexico, officials said. The Pentagon decision significantly ramps up the official response to a “caravan” of migrants from Central America just as the president sought again on Oct. 29 to make the migrant group a focus before the upcoming midterm elections.

The group is still hundreds of miles from the U.S. border, but today the president used Twitter to send out an alarm: “This is an invasion of our Country and our Military is waiting for you!” he wrote.

In the same tweet, Mr. Trump charged, without providing evidence, that “Many Gang Members and some very bad people are mixed into the Caravan heading to our Southern Border.”

“Please go back,” he urged, “you will not be admitted into the United States unless you go through the legal process.”

The president’s tweets revived the issue just days after a shooting that appears to have been at least partly motivated by an “invasion” of migrants claimed 11 lives at a synagogue in Pittsburgh. Hours before he opened fire, the alleged gunman Robert Bowers posted a message on the social network Gab: “hias likes to bring invaders in that kill our people. I can’t sit by and watch my people get slaughtered. Screw your optics, I’m going in.” HIAS is the Hebrew Immigrant Aid Society, a group the gunman had rhetorically attacked previously on Gab because of its efforts to assist refugees.

With days to go before the midterms, the president appears to believe the migrant caravan is a winning campaign issue for his party as Republicans seek to maintain control of Congress. “This will be the election of the caravans, the Kavanaughs, law and order, tax cuts, and you know what else? It’s going to be the election of common sense,” Trump said at a rally in Illinois on Oct. 27.

The U.S. Catholic leadership did not directly respond to the president’s comments but urged “all governments to abide by international law and existing domestic laws that protect those seeking safe haven and ensure that all those who are returned to their home country are protected and repatriated safely.”

They added, “We strongly advocate for continued U.S. investments to address the underlying causes of violence and lack of opportunity in Central America.… An enforcement-only approach does not address nor solve the larger root causes that cause people to flee their countries in search of protection.”

With reporting from The Associated Press

Kevin Clarke is America’s chief correspondent and the author of Oscar Romero: Love Must Win Out (Liturgical Press).