New York and Washington state on Monday vowed to sue President Donald Trump if he scraps a program shielding from deportation immigrants who came to the United States illegally as children.

Trump is expected to announce on Tuesday that he will end the so-called Dreamers program but give the U.S. Congress six months to craft legislation to replace it, according to sources familiar with the situation.

New York Governor Andrew Cuomo, in a joint statement with the state's attorney general, Eric Schneiderman, said "the president's action would upend the lives of hundreds of thousands of young people who have only ever called America their home."

In a separate statement, the attorney general of Washington state, Bob Ferguson, also threatened legal action. "I will use all the legal tools at my disposal to defend the thousands of Dreamers in Washington state," he said in a statement.