The Trump administration said Tuesday that it will cancel more than $900 million in federal grants earmarked for an ambitious California high-speed rail project after the state’s Democratic governor said he now plans to focus on completing a single segment in an interior region.

In addition, the U.S. Transportation Department said it was exploring legal options to recoup $2.5 billion in federal funds already granted to the project by the Federal Railroad Administration, according to a DOT statement.

Initially conceived as connecting San Francisco and Los Angeles with a high-speed train that would slash travel times and transform the state’s economy, California’s project has been beset by cost overruns and delays that have ballooned the price. Governor Gavin Newsom, who took office in January, said last week that the rail as planned “would cost too much and take too long,” and he would instead finish roughly 120 miles of track already under construction in the state’s Central Valley.

The administration’s move comes amid escalating tensions between it and Democratic leaders of the most populous U.S. state. Talks between California and federal officials on vehicle emissions and fuel economy standards have broken down without a deal, three people familiar with the matter said Tuesday. California on Monday led a group of more than a dozen states in a lawsuit to block President Donald Trump from diverting funds from the federal budget to pay for his promised border wall.

“This is clear political retribution by President Trump, and we won’t sit idly by,” Newsom said in a statement Tuesday. “This is California’s money, and we are going to fight for it.”

Trump has lambasted California’s high-speed rail project, in the works for more than a decade, as wasteful and called for the state to return federal funding.

“We want that money back now. Whole project is a “green” disaster!” Trump said in a Feb. 13 tweet.

Newsom said the state is properly using the money to finish the segment in the Central Valley, a mostly rural agricultural region. Newsom said preliminary work on the entire system would continue and that he would seek more federal and private funding. “The train is leaving the station — better get on board!” he tweeted Feb. 13.

In a letter to California officials released by DOT on Tuesday, FRA Administrator Ronald Batory said the state authority responsible for the rail project failed to comply with the terms of the $929.6 million in federal funds.