After reports circulated last week that President Donald Trump had pushed for a policy that would release undocumented immigrants into sanctuary cities, Trump appeared to attempt to put the policy in practice via Twitter on Monday.

"Those Illegal Immigrants who can no longer be legally held (Congress must fix the laws and loopholes) will be, subject to Homeland Security, given to Sanctuary Cities and States!" Trump tweeted just after noon ET.

Last week, the New York Times and other outlets reported that the Trump administration asked Immigration and Customs Enforcement (ICE) about releasing undocumented immigrants into sanctuary cities — cities that have said they will not cooperate with federal immigration agents in some instances. ICE did not respond to Trump's request.

Trump began touting his plan on Twitter over the weekend, claiming he had the "absolute right" to have immigrants transferred to sanctuary cities.

A number of mayors of sanctuary cities released statements over the weekend simultaneously decrying Trump's plan and welcoming immigrants to their cities.

More on this as it develops.