AP Photo/Alex Brandon President Donald Trump speaks during a meeting with Malaysian Prime Minister Najib Razak in the Cabinet Room of the White House, Tuesday, Sept. 12, 2017, in Washington.
"CHAIN MIGRATION cannot be allowed to be part of any legislation on Immigration!" the president wrote on Twitter.
Chain migration refers to a tactic by which lawful permanent US residents sponsor members of their family, particularly non-nuclear ones, who then in turn sponsors several more family members.
Critics of chain migration, such as the Federation for Immigration Reform (FAIR) claim it is a significant factor in bringing large numbers of low-skilled immigrants to the US. In a March 2017 study, FAIR wrote that the "problem with chain migration is that while the United States retains the ability to say 'yes' or 'no' to individual immigrants, the pool of immigrants is self-selecting."
Georgia Rep. Jody Hice, a Republican, introduced a bill to curb chain migration earlier this year called the Nuclear Family Priority Act, which he said in a February statement "would take crucial steps to reform an antiquated immigration selection process and prioritize keeping nuclear families intact."
Trump's demand that there be no chain migration in any immigration reform bills comes on the heels of negotiations with lawmakers over what to do about beneficiaries of the Deferred Action for Childhood Arrivals program, which protects people who are in the US illegally and came to America as minors.
However, Democrats are unlikely to get on board with such a plan. On Thursday, House Minority Leader Nancy Pelosi said a pathway to citizenship would be guaranteed in a bill to protect DACA recipients, which would allow them to sponsor relatives upon becoming US citizens.