The US and Mexico, which do US$600 billion in annual trade, will launch the first new railway link between the two in more than a century, in the Texas border town of Brownsville, Reuters reports.

The West Rail Bypass International Bridge will connect Brownsville with Matamoros, its Mexican neighbour, the US Commerce Department said.

"The West Rail project, which broke ground in December 2010, was designed to expand regional transportation capacity, improve air quality and alleviate urban congestion by re-routing rail traffic out of the most populated areas in both border cities," it said.

There are currently eight rail crossings between the United States and Mexico, according to US Customs. All the locations are equipped with X-ray systems that can scan arriving rail traffic.

The new crossing comes as prominent US politicians, mostly Republicans, have called for tightening controls along the border to cut down on illegal immigrants and illicit goods entering the country.

Mexico is the third-largest bilateral goods trading partner of the United States, according to the Office of the US Trade Representative.