WASHINGTON (AP) — President Donald Trump stepped up his pressure on General Motors to reopen an Ohio manufacturing plant that recently closed and put 1,700 people out of work.

Trump's arm-twisting came in a series of separate tweets on Saturday and Sunday . He capped his weekend rant against the GM with a tweet disclosing that he had vented his frustrations during a conversation with the company's CEO, Mary Barra.

"I am not happy that it is closed when everything else in our Country is BOOMING," Trump wrote. "I asked her to sell it or do something quickly. She blamed the UAW Union — I don't care, I just want it open!"

The union is the United Automobile Workers, which represents the employees who lost their jobs in the Lordstown closure. Trump had previously told a UAW leader, David Green, to "get his act together and produce" for the Lordstown workers. Green didn't respond to a request for comment Sunday.

General Motors said in a statement released Sunday evening that the future of plants scheduled to be closed "will be resolved between GM and the UAW." The automaker also said that it has "opportunities available for virtually all impacted employees" at plants that are to be shuttered.

"We remain open to talking with all the affected stakeholders, but our main focus remains on our employees and offering them jobs in our plants where we have growth opportunities," the company said.

Even as Trump said he talked to Barra, he was calling on GM to reopen its Lordstown plant or find another owner, while insisting that the Detroit automaker "must act quickly."

He also blasted GM for letting down the U.S. and asserted "much better" automakers are coming to the country.

Trump praised Toyota for its investments in the U.S. in an apparent attempt to depict GM as being less committed to its home country than the Japan automaker.

The Lordstown closure has become a hot-button issue in an area of Ohio that is expected to be critical for Trump if he seeks re-election as promised in 2020.

Trump prevailed in Ohio in the 2016 election, a win that helped him win enough electoral votes to become president despite losing the popular vote to Hillary Clinton.

That may be one reason why Trump joined a coalition of Ohio lawmakers in efforts to get the Lordstown plant running again. The tweets marked some of his most pointed criticism of GM so far.

Trump has skewered several other U.S. companies for not doing more to help their country's economy, but his remarks so far have been more bark than bite.

For instance, he has publicly called upon Apple to shift most of its manufacturing from China to the U.S., but the Silicon Valley company continues to make its iPhones and most other products overseas.

Ohio Gov. Mike DeWine, a Republican, last week expressed doubts GM will reopen its Lordstown plant, but he said the automaker indicated it's in talks with another company about using the site.

More than 16 million vehicles were made at the Lordstown plant during its 53-year history until GM closed it earlier this month as part of a massive reorganization. The company also intends to close four other North American plants by early next year.