President Donald Trump, a Republican, and Sen. Chuck Schumer, (D-New York), tussled Monday over who is to blame for the Trump administration's new practice of splitting immigrant families after they're detained at the border.

According to President Trump, the blame falls on the Democratic Party for being "weak and ineffective" on border security.

"There are some who would like for us to look the other way when dealing with families at the border and not enforce the law passed by Congress," said Kirstjen Nielsen, the secretary of homeland security. "Past administrations may have done so, but we will not."

Sen. Schumer argued the decision came from the Trump administration, not the Democrats.

"It wasn't happening when Obama was president, and it wasn't happening for the first year and three months," Schumer said. "What happened was, Stephen Miller, his (the president's) immigration adviser, decided to change the policy. They could reverse it tomorrow."

The House is expected to vote on legislation to address the issue next week.