About half of Americans are concerned that President Trump might launch a nuclear attack without justification, according to a new Washington Post-ABC News poll.

This worry comes as Trump and North Korean leader Kim Jong Un continue to provoke each other on Twitter and follows a previous Post-ABC poll that found a large majority of Americans are concerned about the United States going to war with North Korea.

Overall, 38 percent of Americans trust Trump to handle the authority to order nuclear attacks on other countries, while 60 percent do not. Among those who distrust Trump, almost 9 in 10 are very or somewhat concerned the president might launch an attack.

Combining those results, the poll finds 52 percent of the public overall is concerned the president might launch a nuclear attack without reason, including one-third who say they are “very” concerned, according to the poll.

Partisanship is by far the biggest factor in opinion: Almost 6 in 10 Democrats are “very concerned” about Trump directing an unjustified nuclear attack, compared with about 3 in 10 independents and fewer than 1 in 10 Republicans. Gender is also a factor on this question, with almost twice as many women than men “very” concerned Trump might launch a nuclear attack — 42 percent vs. 22 percent.

Unsurprisingly, views about Trump’s mental fitness are closely tied to concern about his decisions on using nuclear weapons. When asked about Trump’s description of himself as a “very stable genius,” 48 percent said Trump is mentally stable, while 47 percent said he is not. Eighty-four percent of those who say Trump is not mentally stable are at least somewhat concerned that Trump might launch a nuclear attack without justification, while 72 percent of those who say Trump is stable trust him to handle nuclear weapons.

On New Year’s Day, North Korea’s leader warned that “a nuclear button is always on my desk. This is reality, not a threat.” The next day, Trump tweeted that “I too have a nuclear button, but it is a much bigger & more powerful one than his, and my button works.” In turn, North Korea’s official news agency called Trump a “lunatic” and a “loser.” Democrats and some security analysts said that Trump’s tweet might have needlessly provoked Kim at a time when concerns over a nuclear altercation seem more plausible than they have been before. But public tensions have eased somewhat with the beginning of direct talks between South and North Korea.

Even before the “nuclear button” exchanges on Twitter, Americans had concerns about Trump dealing with North Korea. In a November Post-ABC poll, 32 percent said they trusted him a “great deal” or a “good amount” to deal with North Korea. That was higher than the 8 percent who said they trusted Kim to act responsibly in a September Post-ABC poll, but far lower than the 72 percent who trusted U.S. military leaders.

Americans have also expressed concerns that Trump’s tweeting could have serious consequences. In a July Post-ABC poll, 52 percent of Americans said Trump’s tweets were “dangerous.”

The latest survey shows the public does not see much upside in the practice. About two-thirds of adults (66 percent) say that Trump’s use of Twitter is hurting his presidency, while 11 percent say it’s helping the Trump presidency and 20 percent say it makes no difference.

The Post-ABC poll was conducted Jan. 15-18 among a random sample of 1,005 adults reached on cell and landline phones with a margin of sampling error of plus or minus 3.5 percentage points.

Scott Clement contributed to this report.