By Evan Perez, CNN Justice Correspondent

(CNN) -- The Justice Department on Monday unsealed an indictment against three Chinese nationals in connection with cyberhacks and the alleged theft of intellectual property of three companies, according to US officials briefed on the investigation.

But the Trump administration is stopping short of publicly confronting the Chinese government about its role in the breach. The hacks occurred during both the Obama and Trump administrations.

The charges being brought in Pittsburgh allege that the hackers stole intellectual property from several companies, including Trimble, a maker of navigation systems; Siemens, a German technology company with major operations in the US; and Moody's Analytics.

The three charged in the Pittsburgh case are presumed to live in China and are either employed or associated with Guangzhou Bo Yu Information Technology Co., known as Boyusec, court documents say. US intelligence and private cybersecurity experts say Boyusec works as a contractor for the Chinese ministry of state security, that nation's version of the National Security Agency. The court documents unsealed Monday don't mention the Chinese state links.

US investigators have concluded that the three charged by the US attorney in Pittsburgh were working for a Chinese intelligence contractor, the sources briefed on the investigation say. But missing from court documents filed in the case is any explicit mention that the thefts were state-sponsored.

A 2015 deal between then-President Barack Obama and Chinese President Xi Jinping prohibits the US and China from stealing intellectual property for the purpose of giving advantage to domestic companies.

In recent months some US intelligence agencies have concluded that China is breaking the agreement, sources briefed on the matter say. But there's debate among intelligence officials about whether there's sufficient evidence to publicly reveal the Chinese government's role in the infractions, these people say.

Obama administration officials had touted the Obama-Xi agreement, as well as 2014 Justice Department charges against members of the Chinese People's Liberation Army for commercial espionage, for reducing some of the Chinese cyberactivity against companies in the US.

But the 2015 Obama-Xi deal was met with skepticism inside the US agencies whose job it is to guard against Chinese cyberactivity targeting US companies. Some now say there was only a brief drop in the number of cyberspying incidents, if at all.

In the waning months of the Obama administration, intelligence officials briefed senior White House officials on information showing that the Chinese cyberattacks were back to levels previously seen, sources familiar with the matter told CNN. Early in the Trump administration, US intelligence officials briefed senior officials, including the President and vice president, as well as advisers Jared Kushner and Steve Bannon.

At the same time, some Trump administration officials have raised concerns about whether to confront China over the cyber intrusions at a time when the administration is trying to get cooperation from the Chinese government on North Korea and other issues.