NEW YORK — A veteran tabloid publisher testified Tuesday that he pledged to be Donald Trump’s “eyes and ears" during his 2016 presidential campaign, recounting how he promised the then-candidate that he would help suppress harmful stories and even arranged to purchase the silence of a doorman.

The testimony from David Pecker was designed to bolster the prosecution's premise of a decades-long friendship between Trump and the former publisher of the National Enquirer that culminated in an agreement to give the candidate's lawyer a heads-up on negative tips and stories so they could be quashed.

The effort to suppress unflattering information was designed to illegally influence the election, prosecutors have alleged in striving to elevate the gravity of the first trial of a former American president and the first of four criminal cases against Trump to reach a jury.

Pecker is the first witness against Trump, who faces 34 felony counts of falsifying business records in connection with hush money payments meant to prevent harmful stories from surfacing in the final days of the 2016 campaign.

With Trump sitting just feet away in the courtroom, Pecker detailed his intimate, behind-the-scenes involvement in Trump's rise from political novice to the Republican nomination and the White House. He explained how he and the National Enquirer parlayed rumor-mongering into splashy tabloid stories that smeared Trump's opponents and, just as crucially, leveraged his connections to suppress seamy stories about Trump, including a porn actor's claim of an extramarital sexual encounter a decade earlier.

Pecker traced the origins of their relationship to a 1980s meeting at Trump's Mar-a-Lago estate in Palm Beach, Florida, and said the friendship bloomed alongside the success of the real estate developer's TV show “The Apprentice" and the program's subsequent celebrity version.

Their ties were solidified during a pivotal August 2015 meeting at Trump Tower involving Trump, his lawyer and personal fixer Michael Cohen, and another aide, Hope Hicks, in which Pecker was asked what he and the publications he led could do for the campaign.

Pecker said he volunteered to publish positive stories about Trump and negative stories about his opponents. But that wasn't all, he said, telling jurors how he told Trump: “I will be your eyes and ears.”

“I said that anything I hear in the marketplace, if I hear anything negative about yourself, or if I hear about women selling stories, I would notify Michael Cohen," so that the rights could be purchased and the stories could be killed.

“So they would not get published?” asked prosecutor Joshua Steinglass.

“So they would not get published,” Pecker replied.

To illustrate their point, prosecutors displayed a screenshot of various flattering headlines the National Enquirer published about Trump, including “Donald Dominates!’ and “World Exclusive: The Donald Trump Nobody Knows.” The jury was also shown disparaging and outlandish stories about Trump's opponents, including surgeon Ben Carson and Republican Sen. Marco Rubio.

Pecker painted Cohen as a shadow editor of the National Enquirer’s pro-Trump coverage, directing the tabloid to go after whichever Republican candidate was gaining momentum.

“I would receive a call from Michael Cohen, and he would direct me and direct Dylan Howard which candidate and which direction we should go,” Pecker said, referring to the tabloid's then-editor.

Pecker said he underscored to Howard that the agreement with the Trump operation was “highly, highly confidential.” He said he wanted the tabloid’s bureau chiefs to be on the lookout for any stories involving Trump and said he wanted them to verify the stories before alerting Cohen.

“I did not want anyone else to know this agreement I had and what I wanted to do,” the ex-publisher added.

Cohen pleaded guilty in 2018 to federal charges related to his role in the hush money payments. He was once a confidant of Trump's, but their relationship deteriorated in spectacular fashion. Cohen is expected to be a star government witness, and he routinely posts profane broadsides against Trump on social media.

Trump's lawyers are expected to make attacks on Cohen's credibility a foundation of their defense, but in opening with Pecker, prosecutors hoped to focus attention on a witness with a less volatile backstory. Besides maintaining that Trump is innocent, Trump lawyer Todd Blanche told jurors that Cohen cannot be trusted and has “an obsession with getting Trump.”

Pecker's testimony Tuesday followed a hearing earlier in the day in which prosecutors urged Judge Juan M. Merchan to hold Trump in contempt and fine him $1,000 for each of 10 social media posts that they say violated an earlier gag order barring attacks on witnesses, jurors and others involved in the case.

Merchan did not immediately rule, but he seemed skeptical of defense arguments that Trump was merely responding in his posts to others' attacks and had been trying to comply with the order.

Prosecutors allege that Trump sought to illegally influence the 2016 race through a practice known in the tabloid industry as “catch-and-kill” — catching a potentially damaging story by buying the rights to it and then killing it through agreements that prevent the paid person from telling the story to anyone else.

In this case, that included a $130,000 payment to porn actor Stormy Daniels to silence her claims of an extramarital sexual encounter that Trump denies. Prosecutors also described other arrangements, including one that paid a former Playboy model $150,000 to suppress claims of a nearly yearlong affair with the married Trump, which Trump also denies.

In another instance, Pecker recounted a $30,000 payment from the National Enquirer to a Trump Tower doorman for the rights to a rumor that Trump had fathered a child with an employee at Trump World Tower. The tabloid concluded the story was not true, and the woman and Trump have denied the allegations.

As Pecker described receiving the tip in court, Trump shook his head.

Pecker said upon hearing the rumor, he immediately called Cohen, who said it was “absolutely not true” but that he would look into whether the people involved had indeed worked for Trump’s company.

“I made the decision to purchase the story because of the potential embarrassment it had to the campaign and to Mr. Trump,” Pecker said.

In response to the prosecutor’s question about who he understood the boss to be, Pecker replied: “Donald Trump.”

Explaining why he decided to have the National Enquirer foot the bill, Pecker testified: “This was going to be a very big story. I believe it was important that this story be removed from the marketplace.”

If he published the story, Pecker said it would be “probably the biggest sale of the National Enquirer since the death of Elvis Presley.”

Jurors viewed an internal Enquirer email and invoice describing the payments to the doorman to kill his story. One document describes the funds coming from the publication’s “corporate” account. An invoice references an “immediate” $30,000 bank transfer payment for “‘Trump’ non-published story.”

Trump’s 34 felony counts arise from reimbursements that prosecutors say Trump's company made to Cohen for hush money payments and that were falsely recorded as legal expenses.

The charges are punishable by up to four years in prison, though it’s unclear whether Merchan would seek to put him behind bars. A conviction would not preclude Trump from becoming president again, but because it is a state case, he would not be able to pardon himself if found guilty. He has repeatedly denied any wrongdoing.