President Trump on Saturday offered a ray of hope to Big Apple straphangers — hinting at plans to provide federal dough to help complete the long-promised Second Avenue Subway.

“Looking forward to helping New York City and Governor @andrewcuomo complete the long anticipated, and partially built, Second Avenue Subway,” he tweeted. “Would be extended to East 125th Street in Harlem.”

Plans for the line were first approved in 1929, but it took until 2017 — and $4.5 billion — to complete its first leg, from 63rd Street to 96th Street.

The MTA has set aside $535 million in this year’s budget for design and preliminary construction work, and has $1.2 billion in reserve to help pay for the project.

But that would not come close to meeting the estimated $6 billion cost to extend the line to its intended length.

In April, the MTA filed a formal funding request to the federal government asking for a $2 billion allocation for the massive construction project.

Gov. Cuomo reacted to Trump’s remarks with cautious optimism.

“The President’s tweet suggests good news but we have no specific funding or approval and that is all that is relevant,” said spokeswoman Dani Lever.