The US government has released more information on the 2,000km wall that President Trump has ordered built along the Mexican border.
An open invitation will be extended on the government’s FedBizOpps website on 5 March, after which companies that wished to be in involved in the design and build of the structure will have five days to submit "a concept paper of their prototypes".
Offers will be evaluated by 20 March, after which a shortlist will be selected and those chosen will have until 24 March to submit further proposals, include price.
The Department of Homeland Security will then make "multiple awards" by mid-April.
Trump said at the Conservative Political Action Conference last week that the project was "way, way, way ahead of schedule", despite no official timetable having being given.
Some companies have jumped the gun. In August last year, an Israeli firm expressed an interest in building the wall based on its experiences with the Occupied Territories. And in October, Mexican architect Estudio 3.14 proposed a pink wall.
The American Institute of Architects posted an update on its website earlier this month called "Where we stand: immigration and visa restrictions". This said, among other things, that "all people everywhere must be treated fairly and with dignity and respect", and that "immigration policy must ensure our visa system welcomes individuals who want to contribute to society and stops those who seek to harm us".
Image: A border fence between Tijuana, Mexico, on the right, and the US near San Diego on the left (Gordon Hyde)