CEDAR RAPIDS, IOWA - Pete Buttigieg pushed back against criticism from President Donald Trump on the job he did as transportation secretary in former President Biden's administration and declined to say if Biden experienced cognitive decline during his final years in the White House, as he took questions from reporters on Tuesday night.Buttigieg, speaking with reporters after headlining a town hall with veterans in this eastern Iowa city that sparked more speculation that the 2020 Democratic presidential contender is mulling another White House run in 2028, told Fox News that 'right now Im not running for anything."Buttigieg won the 2020 Iowa presidential caucuses and came in a close second in the New Hampshire presidential primary before Biden surged to claim the party's nomination and later the White House.While Iowa's caucuses for half a century kicked off both major political parties' presidential nominating calendars, the Democratic National Committee (DNC) demoted the Hawkeye State on their 2024 schedule, and it's unclear if Iowa will regain its early state status in the 2028 calendar.LESS THAN FOUR WEEKS INTO TRUMP'S SECOND TERM, DEMOCRATS ALREADY EYEING 2028 PRESIDENTIAL RACEBut Buttigieg's visit, along with his announcement in March that he would pass on a 2026 run for a Democrat-controlled open Senate seat in battleground Michigan, his adopted home state, are seen as signals of his interest in a potential 2028 national run.Buttigieg told a Substack author in a live interview hours before the town hall that when it comes to 2028, he would consider "what I bring to the table."But asked by Fox News if the trip to Iowa - where he also gathered with staffers from his 2020 campaign and was followed around by a videographer from his political group Win the Era - was the beginning of an assessment period, Buttigieg said "right now, Im not running for anything and part of whats exciting and compelling about an opportunity like this is to be campaigning for values and for ideas rather than a specific electoral campaign. So that's what I'm about."Told that audience members who said they voted for him in 2020 and would be interested in backing him again if he runs in 2028, Buttigieg said "of course it means a lot to hear that people who supported me then continue to believe in what I have to say."The Cedar Rapids event was hosted by VoteVets, a progressive group that represents veterans and military families in the political process. The group told Fox News that 1,800 people attended the event.WATCH: TRUMP TRANSPORTATION SECRETARY LAYS OUT NEW PLAN TO UPGRADE AGING AIR TRAFFIC CONTROL SYSTEMThe trip by Buttigieg came as he's faced incoming fire in recent days from Trump and Transportation Secretary Sean Duffy over a surge in flight delays and cancellations at New Jersey's Newark Liberty International Airport, which is one of the three major airports that services the New York City metropolitan area.Duffy blames his predecessor at the Department of Transportation and the Biden administration for what he claims was a failure to upgrade the busy airport's air traffic control system.And Trump, last week, also chimed in, claiming that during his tenure as transportation secretary Buttigieg "didnt have a clue. And this guy is actually a contender for president?" Trump added. "I don't think he's going to do too well."The president's jabs came a few days after Buttigieg, pointing to Trump's underwater approval ratings in national polling, said in a social media post that "Donald Trump is the most unpopular 100-day-mark president in modern American history."WATCH: TRUMP TRANSPORTATION SECRETARY LAYS OUT NEW PLAN TO UPGRADE AGING AIR TRAFFIC CONTROL SYSTEMThe Trump administration argues that Buttigieg oversaw a rocky transition of the Newark airport's airspace to the Philadelphia Terminal Radar Approach Control (Tracon) last July.And Duffy, who earlier this week unveiled a major plan to overhaul the nation's aging air traffic control system, claims the Biden administration is to blame for the recent problems, including air traffic control equipment outages."Maybe when you work from home, or maybe when you work from Michigan as a secretary, maybe youre not focused on the real issues that are taking place throughout the airspace," Duffy said, as he took aim at Buttigieg, who lives in Michigan.Buttigieg, responding, told reporters on Tuesday night that "when youre the secretary of transportation, you have a tough job and your responsibility is to fix tough problems. You dont have time to indulge in trying to point fingers or blame other people.""What I can tell you is we inherited a shrinking air traffic control workforce. We turned it into a growing air traffic control workforce," he added. "My successor is, of course, not asking for my advice, but my advice would be to making sure that it grows and actually delivering the technological change thats needed."Buttigieg's Iowa trip also came on the same day that excerpts from a new book offered details on Biden's supposed mental and physical decline during his last two years in the White House.Asked whether Biden experienced cognitive decline, Buttigieg would only say that "every time I needed something from him from the West Wing, I got it."But he said "maybe" when asked whether the Democratic Party would have been better off if Biden had not run for re-election in 2024. "Right now with the benefit of hindsight, I think most people would agree that that's the case."Biden dropped out of the race last July, one month after a disastrous debate performance with Trump sparked a chorus of calls from fellow Democrats for the then-81-year-old president to end his re-election bid. He was replaced at the top of the ticket by then-Vice President Kamala Harris, who ended up losing in November to Trump.