(NewsNation) — Former President Donald Trump‘s campaign has begun requesting information about possible vice presidential picks, beginning a lengthy vetting process of a short list of names.

Less than 40 days remain until the National Republican Convention when Trump could announce his vice presidential pick, though the reveal could come at any moment.

There are new signs the Trump campaign is getting ready for it.

The Associated Press reports that the Trump campaign has been requesting information from his potential vice presidential candidates, sending vetting paperwork to a list of top contenders over the past few weeks.

Those who allegedly received such requests include North Dakota Gov. Doug Burgum, Florida Sen. Marco Rubio, Ohio Sen. JD Vance and South Carolina Sen. Tim Scott.

Begum recently defended Trump outside his New York criminal hush money trial the day of the verdict.

Rubio has also been coming to Trump’s defense, despite challenging him in 2016.

Trump’s campaign, however, denied those reports.

 “Anyone claiming to know who or when President Trump will choose his VP is lying, unless the person is named Donald J. Trump,” campaign spokesperson Brian Hughes told NewsNation.

Sources say Trump trusts the opinion of people around him and sometimes asks them who they think would be a good choice.