Actor George Takei is warning President-elect Donald TrumpDonald John TrumpSenate advances public lands bill in late-night vote Warren, Democrats urge Trump to back down from veto threat over changing Confederate-named bases Esper orders ‘After Action Review’ of National Guard’s role in protests MORE that nuclear weapons are “no game.”

In an op-ed published Thursday in The Daily Beast, Takei cited a recent tweet by the president-elect, which said the U.S. “must greatly strengthen and enhance its nuclear capability” until the world “comes to its sense regarding nukes.”

“I can’t help but feel Mr. Trump treats brinksmanship as some game,” he wrote in the piece. 

“It’s hard to believe he needs reminding, but nuclear weapons are not toys, nor are they chips to be wagered in some kind of high stakes poker match.” Takei said he is one of a number of people who remember the first time atomic weapons were used. ADVERTISEMENT”I had family in Hiroshima when the Enola Gay dropped its deadly payload, obliterating the entire city in an instant,” he wrote. “My aunt on my mother’s side was among the over one hundred thousand dead, along with my baby cousin, who was found cradled in her arms in one of the canals that fan out through the city, their bodies burned nearly beyond recognition as she attempted to shield her child from the blast and the fire.” The “Star Trek” alum has been highly critical of Trump throughout his presidential campaign and transition. The country must now acknowledge that a man who “apparently lacks the self-control to keep his fingers from tweeting, now literally has those same fingers on the nuclear button,” he wrote. “But beyond the question of temperament, I must ask: Does Donald Trump understand the true horror of what he can unleash in an instant?” Takei said he is hopeful that when the president-elect talks about the world “coming to its senses about nukes,” he includes the U.S. and himself. “If his pre-inaugural actions are any indication, it is Trump, above anyone, who must come to his senses about what these weapons represent,” he wrote.