Trump had once courted Heitkamp, even inviting her to NY to discuss a Cabinet post soon after his 2016 election victory.
Heitkamp says she also talked about worldwide trade, oil prices and health care-related issues with the president.
Trump also hit Heitkamp on voting against the GOP tax bill that passed, accused her of voting against cracking down on so-called "sanctuary cities" and not being a dependable vote on his next U.S. Supreme Court pick now that Justice Anthony Kennedy has announced his retirement-although Heitkamp did vote to confirm Trump's first appointee, the very conservative Neil Gorsuch.
However, he has also at times praised Heitkamp - including at a September 2017 event in North Dakota, where Trump called Heitkamp a "good woman" and invited her onstage.
President Donald Trump is offering a hearty endorsement to congressman Kevin Cramer, the man he says will be "the next United States senator from the great state of North Dakota". Trump won North Dakota by a large margin in 2016.
Trump called instead for the election of Republican U.S. Rep. Kevin Cramer, one of his staunchest allies in Congress.
Trump wants those who ‘invade' sent right back
Intense criticism of the policy caused Trump to sign an executive order last week to end the separation of families. Trump posted on Twitter Sunday afternoon.
Called to the microphone by the president, Cramer thanked Trump for rolling back federal regulations, cutting taxes and, "on behalf of the most vulnerable forgotten people, the unborn babies, thank you for standing for life".
Heitkamp joined Democrats in voting against tax cuts Trump enacted previous year.
Trump went farther than that in attacking Heitkamp, calling her a "liberal Democrat" who blindly follows "Chuck and Nancy".
Dozens of farmers drove tractors and other farm equipment to the rally on Wednesday, just hours before Trump spoke at Scheels Arena.
Mike Murphy, a GOP strategist, said having a Supreme Court retirement and confirmation in a midterm election year will make a "red-hot" election year even hotter - especially because a fifth consistently liberal justice could bring hot-button issues like abortion and gay rights onto the court's docket.
"Radical Democrat protesters, they really want anarchy", he said. We have to pick one that's going to be there for 40 years, 45 years.
In Fargo, Trump decried Wednesday what he deemed unfair treatment from other countries and said he aims to make trade "fair and reciprocal". John Hoeven, R-N.D., followed him as he exited Air Force One at the North Dakota Air National Guard Base next to Hector International Airport.