The deputy director of the CIA said that the United States has carried out more extensive espionage activities against China to deal with dual threats.

CIA Deputy Director Michael Ellis said on Tuesday that the United States is conducting a broader espionage campaign against China - including Chinese companies - in response to the country's status as a dual military and economic threat.

In a rare public speech, Ellis said the nature of intelligence collection had changed dramatically since the CIA and other intelligence agencies were created to spy on the Soviet Union during the Cold War.

Ellis told a cybersecurity conference in Washington that China "poses a very different threat to us than past geopolitical rivals because the competition is economic."

Western officials say that under Communist rule, China did not have an independent business community like the one in the United States or much of Europe. Ellis said this makes Chinese companies in areas such as artificial intelligence, semiconductors and biotechnology legitimate targets for espionage.

Ellis said the CIA needs to expand its espionage authority because valuable intelligence about these technologies "cannot be found in the same channels that obtain political or military intelligence." He added that the information "exists in the private sector - or in those entities in China that are arguably closest to the private sector."

Ellis' comments were a subtle departure from precedent set by previous administrations, which have typically distinguished between what the United States considers acceptable espionage, such as intelligence collection for defense and foreign policy purposes, and economically motivated espionage.

For example, the Obama administration often publicly accused China of hacking to steal intellectual property from U.S. companies, eventually signing an agreement with Beijing in 2015 in which both sides agreed not to engage in economic espionage. The United States later accused China of violating the agreement.

However, U.S. officials have long acknowledged privately that it is difficult to define what constitutes legitimate espionage. But they have traditionally not expressed this in public.

"We're always collecting intelligence in some way, shape or form," Ellis said in a brief interview after the public speech. "The difference now is that it's not just about tanks, missiles and submarines."

The timing of Ellis's remarks was also significant. President Trump is scheduled to receive Chinese leader Xi Jinping for a state visit this month. Competition around artificial intelligence and trade is expected to be among the topics discussed during the summit.

Ellis spoke on the same day that the Trump administration issued a public advisory warning that Chinese artificial intelligence companies were engaging in "industrial-scale" trade secret theft from their American counterparts.