US President Joe Biden visited the site of a toxic train crash Friday for the first time since the disaster more than one year ago in rival Donald Trump's political heartland.

The 81-year-old Democrat faced protests as his motorcade arrived in East Palestine, Ohio, where Republicans and locals have criticized him for not coming sooner.

A Norfolk Southern train carrying hazardous materials derailed in East Palestine on February 3, 2023, resulting in a pile of burning rail cars that created a pall of toxic gas and forced the evacuation of residents.

"While there are acts of God, this was an act of greed that was 100 percent preventable," Biden said during his visit, accusing the rail firm of failing to meet safety standards.

A number of protesters in the village carried signs supporting Trump, who is almost certain to be Biden's Republican challenger in November's US presidential election.

At least one demonstrator raised a middle finger at the motorcade while others carried signs criticizing the government's response.

East Palestine residents have complained of ongoing air and water contamination from the crash, which derailed 38 of the train's 150 cars and released chemicals such as vinyl chloride -- known to cause cancer.

After the derailment, emergency workers then deliberately burned off more of the materials in other tank cars, releasing dangerous gases into the air and forcing the evacuation of some 2,000 people from their homes.

Trump visited East Palestine shortly after the crash and accused Biden of abandoning the village, which is deep in one of the most Republican corners of Ohio.

Republicans also slammed the pace of the administration's response to the train wreck, as they tried to win over blue-collar voters who will be crucial in November's election.

But while Ohio voted for Trump in 2016 and 2020, Democrats are hoping it could be turned back into a swing state this year as it had been in some previous US elections.

Democrats were given heart when Ohio voted last year to enshrine abortion rights in the constitution, angering conservatives.