Update: This story has been updated with new details about President Donald Trump's border wall funding plans.

Dive Brief:

• U.S. Customs and Border Protection (CBP) on Thursday announced the four winners of bids to build prototypes for a proposed 2,000-mile-long barrier along the U.S.-Mexico border, The Washington Post reported.

• Caddell Construction, Montgomery, AL; Fisher Sand & Gravel/DBA Fisher Industries, in Tempe, AZ; Texas Sterling Construction, in Houston, TX; and W.G. Yates & Sons Construction, in Philadelphia, MS, were selected from more than 200 companies, of which 20 were named finalists, that submitted bids.

• The concrete wall must be 30 feet tall, difficult to scale and visually appealing from the U.S. side. CBP also requested proposals for walls built out of alternative materials. It plans to announce those winning proposals at a later date. The prototypes will be built in San Diego.

Dive Insight:

The president had pledged to shut down the government if Congress doesn't include funding for his border wall in its 2018 budget. Trump, however, changed course on Friday, saying he wouldn't force such a shutdown if border wall funding wasn't realized, The Washington Post reported.

So far, however, paying to build a more extensive barrier between the U.S. and Mexico hasn't gained much traction. Congress has reserved $20 million of Homeland Security funds that could be used on the project if necessary. And a House Appropriations Committee last month approved $1.6 billion for the project, which would get it through the prototype phase. The Senate still needs to approve that request, where it’s likely to be met by more opposition.

When the White House does eventually ask for the full funding amount, that figure will be steep. Earlier this year, the Department of Homeland Security cited a $22 billion price tag for the project. And despite Trump’s assertions, Mexico, for its part, continues to say it won’t pay for a wall.

House Republicans who were gearing up to discuss an appropriations bill that would shift disaster relief funds — amounting to roughly 6% of FEMA’s annual budget — to border wall construction will likely return to the drawing board in light of Hurricane Harvey, Time reports.

Disputes filed by two companies who were informed in advance that their bids were not selected pushed back the expected announcement from June. Those protests have since been dismissed, according to The Post, but one of the companies has said it plans to sue. Other companies whose bids were rejected could challenge the decision, causing further delays.

Prior to the earlier challenges' dismissal, construction on the prototypes was expected to begin as early as November. With those disputes settled, for now, it’s possible that construction could start sooner.

Meanwhile, CBP is already planning to build a 3-mile stretch of border wall through a wildlife refuge in South Texas using its existing funds.