The House of Representatives yesterday voted in favour of US Government funding for training both gardaí and the Police Service of Northern Ireland.
It is the first time that either of the two Houses of Congress has voted in favour of such funding for a Northern Ireland police force.
If passed into US law, the measure will authorise the US Government aid agency, US Aid, to fund training of both police forces and encourage inter-force co-operation.
The US Congress has long resisted funding Northern Ireland police because of human rights concerns.
However, yesterday's measure, introduced by New York Congressman Mr Joe Crowley, was not debated and was entered as an amendment to a State Department Reauthorisation Bill, which was passed by 382 votes to 42.
The Bill will allow US aid to provide "computer-based, human rights and other professional training" to the Police Service of Northern Ireland and also to provide training to gardaí.