President Donald Trump delivers remarks at American Center for Mobility in Ypsilanti, Michigan with General Motors CEO Mary Barra and other auto industry executives on March 15, 2017. Nicolas Kamm | AFP | Getty Images

President Donald Trump and General Motors CEO and Chairman Mary Barra had a "productive and valuable" meeting Thursday, the auto executive said as she exited the White House. Barra did not offer any other details about her private sit-down with the president, which comes at a critical time for GM's business operations and automotive industry. In addition to facing ongoing concerns regarding trade, China and national fuel economy regulations, GM was selected Tuesday as the lead company over Ford Motor and Fiat Chrysler to negotiate new labor contracts with the United Auto Workers union. All four of those topics were expected to be among the "wide ranging" discussions during the afternoon meeting, according to two people briefed ahead of it. Expected attendees included Barra, Trump, members of GM's policy team and Trump's top economic advisor Larry Kudlow. "We had a productive and valuable meeting," Barra told reporters as she walked to her GMC Yukon XL sport utility vehicle to leave the White House. A GM spokesman declined to offer any additional comments outside of Barra's remarks after the meeting. The company earlier in the day declined to say what was on the agenda, saying "executives meet with policy makers on a regular basis." The White House confirmed the sit-down after Reuters reported the meeting Wednesday night. Since Trump was elected to office in 2016, GM and other automakers have routinely briefed him and his administration on their operations — everything from policies to major investment announcements.

Fine line

Automakers, specifically GM, have walked a fine line when it comes to briefing the president. He's often criticized or commended automakers' decisions on Twitter — sometimes even before the companies have a chance to announce their own news. Less than a week ago, Trump attacked GM for its production facilities in China and questioned whether the automaker should move the operations to the U.S. Trump, in a tweet, said GM, "once the Giant of Detroit, is now one of the smallest auto manufacturers there. They moved major plants to China, BEFORE I CAME INTO OFFICE. This was done despite the saving help given them by the USA. Now they should start moving back to America again?" Tweet Many of the claims in the tweet against the Detroit automaker were misleading or inaccurate, according to industry data and officials. It came a day after Bloomberg News reported GM's 46,000 unionized workforce in the U.S. trails Ford by about 9,000 and Fiat Chrysler by roughly 1,200.

California

Trump last month also called out the automakers, specifically Ford, for not supporting his efforts to roll back Obama-era fuel efficiency rules for new vehicles. He called auto executives "foolish," said the founders of Ford and GM are "rolling over" at the "weakness of current car company executives." Tweet The attacks came after Ford, Honda, BMW and Volkswagen reached a voluntary agreement last month with California on fuel economy standards. The deal incorporated more stringent emissions rules adopted by former President Barack Obama that Trump is intent on easing. While many automakers have supported reevaluating the rules to address current market conditions of lower gas prices, all-electric vehicles and increased sales of trucks and SUVs, none of the major automakers support Trump's plan to roll back Obama-era standards. The administration, in the meantime, is preparing a plan to do just that. Two U.S. agencies are writing new rules that would revoke California's authority to set its own emissions standards and preempt states from setting their own vehicle rules, Reuters reported Thursday, citing two people briefed on the matter.

Labor union talks