WASHINGTON (Reuters) - President Donald Trump asked U.S. Congress in his State of the Union address on Tuesday to pass legislation to boost the nation’s aging infrastructure, without providing details on how to go about paying for it or how much it would cost.

FEBRUARY 5, 2019 - WASHINGTON, DC: President Donald Trump delivered the State of the Union address, with Vice President Mike Pence and Speaker of the House Nancy Pelosi, at the Capitol in Washington, DC on February 5, 2019. Doug Mills/Pool via REUTERS

Trump, who vowed in 2016 as a candidate to back $1 trillion of infrastructure spending over 10 years, was vague about his plans.

“Both parties should be able to unite for a great rebuilding of America’s crumbling infrastructure,” Trump said in his speech.

“I know that the Congress is eager to pass an infrastructure bill -- and I am eager to work with you on legislation to deliver new and important infrastructure investment, including investments in the cutting edge industries of the future. This is not an option, this is a necessity.”

Trump did not put a price tag on the effort, in contrast to his 2018 State of the Union address when he called on Congress “to produce a bill that generates at least $1.5 trillion for the new infrastructure investment we need.”

A number of administration officials, including Acting Environmental Protection Agency chief Andrew Wheeler, will be holding events around the country this week to discuss infrastructure, while a U.S. House panel will hold a hearing on infrastructure needs on Thursday.

In February 2018, Trump asked Congress to authorize $200 billion in federal money over 10 years to spur road, bridge and other projects mostly funded by states, cities and the private sector.

That plan was roundly criticized and never voted on in Congress, which was then controlled by Republicans. Democrats now control the House of Representatives and are demanding that Trump back new revenue as a condition of moving forward with an infrastructure plan.

Reuters reported last month that the administration was considering an infrastructure plan for as long as 13 years.

Representative Peter DeFazio, who chairs the House Transportation and Infrastructure, said on Tuesday he has been holding discussions with administration officials about an infrastructure plan.

DeFazio says the United States has at least $2 trillion in infrastructure needs, including 140,000 bridges that need substantial attention and 40 percent of the nation’s highways that need to be rebuilt. “It is past time to make these investments,” DeFazio said. “We are in a crisis.”

DeFazio’s committee will hear Thursday from Amtrak chief executive Richard Anderson, Minnesota Governor Tim Walz and Los Angeles Mayor Eric Garcetti.

Democrats previously proposed raising $500 billion by issuing 30-year bonds and using revenue from indexing fuel taxes to rise with inflation.