The Trump administration has dispatched letters to officials in sanctuary cities, threatening to withhold federal funds if they refuse to cooperate with an immigration crackdown.

In the latest effort to lever those communities that have said they will not cooperate with Donald Trump’s proposals, the US Department of Justice sent letters to nine cities and jurisdictions, warning them to fall into line.

Alan Hanson, the acting assistant attorney general for the Justice Department’s grant-making arm, warned the cities that they are required by law to provide proof to they are complying with federal immigration law.

“Failure to comply with this condition could result in the withholding of grant funds, suspension or termination of the grant, ineligibility for future… grants, or other action, as appropriate,” Mr Hanson wrote.

The letters went to officials in California and in major cities including New York, Chicago, Philadelphia and New Orleans, all places the Justice Department's inspector general has identified as limiting the information local law enforcement can provide to federal immigration authorities about those in their custody.

US Sanctuary Cities: We in California have a responsibility to say 'no'

Attorney General Jeff Sessions has increasingly warned the administration will punish communities that refuse to cooperate with efforts to find and deport immigrants in the country illegally.

In a statement issued on Friday, the Justice Department said the recipients of its letters were “crumbling under the weight of illegal immigration and violent crime”.