Gov. Mark Dayton and Attorney General Lori Swanson on Tuesday called on President Donald Trump and other federal officials to stop separating children from their parents at the U.S.-Mexico border.

In a statement Tuesday afternoon, the DFL governor said Minnesota has not been asked to send any National Guard troops or equipment to help with immigration enforcement on the border, but that he would refuse to comply with any requests in the future, unless the Trump administration rethinks its zero-tolerance policy and stops removing children from parents when they are arrested at the border.

“I will refuse to provide any such aid, until the Trump Administration stops its immoral and un-American ripping apart of immigrant families,” Dayton said.

Meanwhile, in a letter to U.S. Attorney General Jeff Sessions and U.S. Department of Homeland Security Secretary Kirstjen Nielsen, Swanson and a group of 20 other Democratic state attorneys general called the policy of separation “inhumane,” adding that it “also raises serious concerns regarding the violation of children’s rights, constitutional principles of due process and equal protection, and the efforts of state law enforcement officials to stop crime.”

In a statement, Swanson, who is also a DFL candidate for governor, reiterated her opposition to the policy, which has resulted in nearly 2,000 children being separated from their parents since April.

“Splitting children from parents is inhumane, and we can do better as a nation,” she said.

Under the policy, any adult crossing the border outside of official ports of entry to claim asylum faces prosecution, whether or not they have a criminal history. Children traveling with them are separated while adults go through the legal process, a change from the government’s previous practice of releasing families together while adults await prosecution.

Facing outcry over the policy, federal officials have said that the children are well cared for in federal detention centers.

In the letter, the attorneys general argue that the policy of separation is not in the best interest of the children who end up at the border.

“Put simply, the deliberate separation of children and their parents who seek lawful asylum in America is wrong,” they wrote. “This practice is contrary to American values and must be stopped. We demand that you immediately reverse these harmful policies, as it is in the best interests of the children and families affected.”

The Associated Press contributed to this report.