President Donald Trump signed an executive memorandum on Thursday that would impose retaliatory tariffs on up to $60 billion in Chinese imports.

"This is the first of many" trade actions, Trump said as he signed the memo.

The new measures are designed to penalize China for trade practices that the Trump administration says involve stealing American companies' intellectual property. They will primarily target certain products in the technology sector where China holds an advantage over the U.S.

The new measures follow a so-called 301 investigation led by U.S. Trade Representative Robert Lighthizer into China's potentially unfair trade practices with the U.S.

Lighthizer's office will publish a list of targeted products in 15 days, and there will be a 30-day period for public comment, according to senior administration officials.

The U.S. Trade Representative's yet-to-be-released report covers 1,300 product lines, the administration officials said.

The bottom line, said Trump's trade director, Peter Navarro, on Thursday, is that the U.S. is "strategically defending itself against economic aggression." The president is standing up for American corporations, he added.

Lighthizer told lawmakers on Thursday, however, that China is likely to retaliate against the tariffs by targeting U.S. agricultural products that are reliant on the Chinese export market.

The Trump administration had previously signaled that the tariffs would apply to at least $30 billion in Chinese imports, multiple news outlets reported. Trump himself has pushed for $60 billion in tariffs on Chinese goods.

In the Senate Finance Committee on Thursday before Trump's announcement, Lighthizer outlined the Chinese products that will be subject to the new tariffs, including aeronautics, modern rail, new-energy vehicles and high-tech products.