President Trump plans to donate his salary from the last quarter to the Department of Transportation to facilitate infrastructure development, the White House announced on Tuesday as administration officials worked to draw attention to the roll-out of Trump's infrastructure plan.

The president's salary from the last quarter will go toward InfraGrant, a program that prioritizes grants for state and local projects, Transportation Secretary Elaine Chao told reporters at the White House on Tuesday.

The grant program "directly reflects the president's proposal by providing dedicated discretionary funding" toward "critical issues" facing infrastructure projects, Chao said.

Trump has promised to donate his salary while in the White House, and his last donation was to the Department of Health and Human Services to combat the opioid epidemic. He had given prior salaries to the Department of Education and the National Park Service.

Chao defended Trump's infrastructure proposal on Tuesday amid questions about the low amount of federal funding the plan would provide. Under the administration's proposal, Congress would appropriate $200 billion over the next 10 years to spur what White House officials have said will be more than $1.5 trillion total investment in infrastructure over the next decade.

The Transportation secretary noted Trump's infrastructure plan would place special emphasis on rural development.