President Donald Trump on Tuesday approved a $3 billion aid package for the wall along the U.S.-Mexico border, a measure that could further complicate the effort to build the $19.7 billion project.

Trump announced the grant program for the U-turn project on Twitter after signing legislation that would boost funding for the project.

He also approved a waiver of the requirement that U.s. taxpayers foot the bill for the border wall and promised a review of a law requiring a 30-day delay on new construction projects.

The $3B grant is aimed at paying for the $18.5 billion project that the Trump administration has been pushing since May.

The wall would be constructed at the southernmost point of the border, which includes parts of San Diego, Nogales and the Mexican border town of Ciudad Juarez.

The program is a $5.5 trillion package that is expected to raise $11 trillion over 10 years.

Trump signed the bill last month in response to the massive influx of unaccompanied children from Central America that has killed more than 300 people in the past two years, according to the nonpartisan Migration Policy Institute.

The grant, which covers the wall’s construction, is the first part of a $1.9 trillion package to be funded by Congress in the fiscal year that begins Sept. 30.

That money will be spent on new border fencing, border roads and other infrastructure projects, according the bill.

Trump has vowed to keep his promise to build a wall along a 2,000-mile stretch of the U., Mexico and Texas border, though the project has been delayed several times and has been repeatedly challenged in court.

The Department of Homeland Security and the Border Patrol have been scrambling to finish the construction of the $4.7 trillion wall and get it up and running in time to begin the fiscal 2019 fiscal year.

The bill also includes money for the construction and operation of a fence along parts of the southern border with Mexico.

It also includes funding to purchase more fencing at a cost of $1 billion, the bill said.

The White House said the grants are part of an ongoing effort to make the border more secure.

“Our goal is to secure our southern border so that the U.-turn program does not cost us a dime more than it already does,” Trump said in a statement.