TIJUANA, Mexico • Parts of prototypes for United States President Donald Trump's border wall with Mexico have been seen behind the current border fence, from the Mexican side of the border in Tijuana, Mexico.

The US Customs and Border Protection has released photos showing the construction of the prototypes for the controversial border wall in California's San Diego County.

Eight 9m-tall prototypes, four made of concrete and four of other materials, will be erected.

Media reports said that work on the prototypes started a week ago and all eight mock-ups will be completed in a month.

Following the completion of the prototype, each model will undergo testing to measure resistance to tampering and penetration.

Mr Trump has said he will pick the winning design in a month even though no funding has been approved by Congress yet for a border wall which he first proposed on his campaign trail to stop illegal crossings.

REUTERS