While President Trump looks to minimal sources to continue funding more United States-Mexico border construction projects — mainly bollard-style fencing — Congress is hiding some of the most commonly proposed sources of money.

On Tuesday, White House Press Secretary Sarah Huckabee Sanders said the administration was looking to “specific pots of money” to fund the bollard fencing that the Department of Homeland Security (DHS) has been constructing in San Diego, California; Calexico, California; El Paso, Texas; and Santa Teresa, New Mexico.

As Breitbart News Political Editor Matt Boyle notes, Sanders and the Trump administration have provided no details as to where such funding would come from.

Two funding sources most commonly invoked by conservatives — fines on illegal aliens and taxing remittances — are tied up behind a Republican-controlled Congress that has provided less than $2 billion so far for border barriers under Trump.

Even if Trump wanted the Immigration and Customs Enforcement (ICE) agency to use fines, asset seizures, and other financial penalties to pay for the $25 billion southern border bollard fence, the money would have to be appropriated through Congress, experts tell Breitbart News.

Unlike the United States Citizenship and Immigration Services (USCIS) agency, which has near full control over its revenues, ICE revenues largely go to the Treasury Department.

This, for example, makes it impossible for Trump to use the roughly $10.2 million that businesses were fined in Fiscal Year 2018 for hiring illegal aliens by ICE for the bollard fence without the money being approved by Congress.

Even when ICE seizes the assets of illegal aliens living in the U.S., that revenue goes into a separate forfeiture fund that is restricted for use by federal rules, an immigration expert says.

The second alternative revenue source has been touted for years by proponents of a national immigration policy that benefits American citizens is taxing remittances.

In March of last year, Rep. Mike Rogers (R-AL) introduced legislation to fund all border construction projects through a tax on remittances, through which an estimated $54 billion is sent back to the home countries of illegal aliens and legal immigrants who are currently in the U.S.

The legislation would have imposed a two percent tax on all remittances, but the plan was never prioritized by the White House or the Republican Congress and was not included in the GOP’s overhaul of the tax code that was passed last year.

Immigration experts have suggested similar tax plans, such as a two percent fee on wire transfers out of the nation, similar to the one percent wire transfer fee the state of Oklahoma imposes, which brings in about $12 million annually.

Such fee and tax plans, similar to the ICE revenue, would have to go through Congress to have the money specifically appropriated towards funding Trump’s bollard fencing, an unlikely outcome for the incoming Democrat majority in the House.