TikTok and the video sharing app's parent company ByteDance sued rival app Triller on Wednesday in a countersuit over patent infringement claims.

Chinese-owned TikTok filed a complaint in San Francisco federal court that Triller’s lawsuit, filed over the summer, has “cast a cloud” over TikTok and ByteDance, “causing uncertainty” for the company. 

The complaint also denies Triller’s allegations that TikTok infringed on Triller’s patent. 

“A judicial declaration is necessary to resolve the real, immediate, and justiciable controversy concerning these issues and to determine the respective rights of the parties regarding the ’429 patent,” TikTok’s complaint states. 

Triller, a U.S.-based video-sharing app, filed a lawsuit in July alleging that TikTok has been using its technology for years. 

In response to TikTok’s countersuit, Triller CEO Mike Lu maintained that the Chinese company stole its technology and said Triller is prepared for a “David and Goliath” style court battle. 

“We will not be intimidated and we will not back down. We may be small, but we have right on our side,” Lu said in a statement.

“This is a David and Goliath story, and we look forward to our day in court, as well as our David and Goliath ending,” the CEO added. “We’re not only standing up for Triller; we’re standing up for its investors, its entrepreneurs, its employees, and all U.S.-based businesses who have to deal with this on a daily basis.”

The legal battle between the tech companies comes as TikTok faces attempts from the Trump administration to block TikTok’s use in the U.S.

The Trump administration has pushed back hard against TikTok, as well as Chinese technology groups such as telecommunications company Huawei, citing national security concerns. 

A federal judge said earlier this month that he would hold a hearing on Nov. 4 — the day after Election Day — over whether to allow President Trump’s efforts to overhaul how TikTok operates in the U.S.