Former US President Donald Trump claims that the current administration’s incompetence could lead to a worsening of the Ukraine crisis.

“We have incompetent people in charge,” Trump said at a rally in Greenwood, Nebraska, on Sunday, warning that the situation in Ukraine is “a very dangerous thing” and that “this could be a world war.”

Trump slammed US Vice President Joe Biden once more, calling his performance a “unmatched and unmitigated failure” and claiming that Biden has allegedly done more damage in 16 months than the previous five worst presidents combined.

Biden is “embarrassing” the US, according to Trump, and world leaders, including Russian President Vladimir Putin, no longer respect the US. “He throws the word [‘nuclear’] around all the time because he doesn’t respect our leadership,” Trump claimed.

Meanwhile, Russian Foreign Minister Sergey Lavrov has repeatedly stated that Russia is not threatening anyone with nuclear war, but that Western countries and Ukraine have been “playing with the words “nuclear war” for a long time.

Other presidents, according to Trump, are not returning Biden’s calls and “want nothing to do with him except take advantage of us.” Biden should “take a cognitive test and release the results for the entire world to see,” according to the former president.

Trump cited the United States’ record inflation, claiming that Biden and his administration are attempting to shift blame by accusing Putin of being to blame for the rising prices. “Why the hell not blame Putin,” Trump mockingly said.

Joe Biden’s approval rating hit lowest point of any president before him after a year and three months in office. According to a Washington Post-ABC News poll conducted on April 24-28, Biden’s overall disapproval rate stands at 52 percent. 47 percent of Americans disapprove of the president’s handling of the Ukraine issue in particular.