White House says some employees were fired by mistake

The president of the country’s largest federal employee union slammed the Trump administration’s planned mass layoffs, calling the move a "blatant violation of the principles of fairness and merit that are supposed to govern federal employment."

"These firings are not about poor performance -- there is no evidence these employees were anything but dedicated public servants. They are about power,” said American Federation of Government Employees President Everett Kelley.

"They are about gutting the federal government, silencing workers, and forcing agencies into submission to a radical agenda that prioritizes cronyism over competence," Kelley added.

This new wave of firings could impact more than 200,000 workers hired by the federal government within the last two years, according to data from the Office of Personnel Management.

-ABC News' Peter Charalambous and Ben Siegel

During a press conference with Indian Prime Minister Narendra Modi, President Donald Trump was asked about his administration's comments that Ukraine will not be able to gain NATO membership or its pre-2014 borders during negotiations to end the war started by Russia.

"You have suggested several things Ukraine should give up. ... What should Russia give up?" a reporter asked.

Like he has before, Trump claimed the war would have never happened if he were president.

"But as far as the negotiations, it's too early to say what's going to happen," he said. "Maybe Russia will give up a lot. Maybe they won't. It's all dependent on what is going to happen. The negotiation really hasn't started."

The Trump administration has begun mass layoffs across multiple federal agencies, a move that is expected to affect thousands of employees across the government, sources familiar with the matter told ABC News on Thursday.

The firings initially affected probationary employees, recent hires who joined the federal workforce within the last one to two years, depending on the agency, who have fewer protections.

Among the agencies experiencing layoffs are the Department of Education, the Consumer Finance Protection Bureau, the Office of Personnel Management, the Environmental Protective Agency, the General Services Administration and the Small Business Administration.

Additional agencies were directed to begin their layoffs Thursday, sources said. At some agencies, workers received written notice via email that they had been let go.

At OPM, workers joined a call with a prerecorded message from the acting director notifying them of their firing, according to someone familiar with the call. There were about 200 probationary workers on that call, the sources said.

Prior to the layoffs, agencies had been directed by OPM to compile lists of probationary employees at their agencies, sources familiar with the matter told ABC News.

-ABC News' Will Steakin, Ben Siegel and Katherine Faulders

Trump is hosting Indian Prime Minister Narendra Modi in the Oval Office.

Trump said they'd be talking about trade, including the possibility of India buying more American oil and gas.

"We've had a wonderful relationship, and we kept the relationship during the four year period," Trump said.

Modi has been prime minister of India since 2014. Reflecting on Trump's first term, Modi said, "We will continue to advance the India-U.S. strategic partnership with the same aplomb, with the same trust and with the same excitement."