A must-pass Homeland Security funding bill proposed by House Republicans on Tuesday includes $1.6 billion to fund the beginning of a border wall along the Mexican border that President Trump promised voters in 2016.

The money in included in the fiscal 2018 Department of Homeland Security appropriations bill, which is up for a subcommittee vote on Wednesday.

The $44.3 billion measure pays for a broad array of federal security programs, including aviation security, border and immigration enforcement, customs, cyberterrorism protection, drug smuggling prevention and natural disaster response.

The legislation includes $1.6 billion for a "physical barrier construction along the U.S. southern border."

The move will appease Trump and conservatives, but will likely set up a spending showdown with Democrats, who have pledged to block spending legislation that funds the wall.

The bill includes funding increases aimed at enhancing border security, including $100 million to hire 500 new border patrol agents and $106 million for new aircraft technology for use along the border.

"This funding bill provides the resources to begin building a wall along our southern border, enhance our existing border security infrastructure, hire more border patrol agents, and fund detention operations," said Homeland Security subcommittee Chairman John Carter, R-Texas. "Additionally, this bill will increase funding for Immigration and Customs Enforcement, support grants in cases of emergency and natural disaster, and provide critical resources to protect our cyber networks."