President Donald Trump was to meet with Senate Republican tax-writers on Monday at the White House to scope out an end-game strategy for sweeping tax legislation, ahead of a crucial vote on the Senate floor that could come as early as Thursday.

But even before his face-to-face with Senate Finance Committee Chairman Orrin Hatch and four others from the panel, Trump took to Twitter to advocate for last-minute changes to the Republican bill as a way to improve benefits for businesses and middle-class Americans.

"The Tax Cut Bill is coming along very well, great support. With just a few changes, some mathematical, the middle class and job producers can get even more in actual dollars and savings and the pass through provision becomes simpler and really works well!" the president tweeted.