Washington: A key vote on immigration reform was postponed in the US Congress Thursday as Republicans failed to garner enough support for the legislation that would address the issue of family separation.

First, a hardline proposal was defeated - as expected - by 193 votes to 231.

Then voting on a compromise bill between the party's hard-right and moderate wings was pushed back to at least Friday, according to a House aide.

The legislative drama came a day after US President Donald Trump - in a stunning about-face - moved to end the practice of splitting migrant families after they cross into the US from Mexico.