Blackstone's Jonathan Gray believes China and the U.S. will resolve their trade conflict.

CNBC's David Faber asked the executive about the escalating trade war between the U.S. and China.

"I'm still optimistic," he said Friday. "My optimism comes from the fact it's in the parties' interest that if we stop trade and investment between these two big countries it wouldn't be good."

On Monday, President Donald Trump's administration announced it will impose 10 percent tariffs on about $200 billion of imports from China effective Sept. 24. Trump, in a statement, said the tariffs would rise to 25 percent on Jan. 1, 2019. The following day, China retaliated by announcing it will institute new tariffs on U.S. goods worth $60 billion.

The investor also expressed his bullishness over the state of the U.S. economy, citing recent consumer confidence, unemployment claims and small business confidence data reports.

"We still see incredibly strong signs in the U.S.," he said. "In terms of economic activity, we're pretty positive in the U.S."

Gray became the firm's president and chief operating officer earlier this year. The executive previously helped build Blackstone's real estate investment business.

Blackstone manages private equity, credit and hedge fund investment strategies for its clients. The firm has $439 billion of assets under management through June, according to its website.