Reform leader listed as main speaker at Chicago event that will also feature Harald Vilimsky of far-right Freedom party

Nigel Farage speaking in the Commons. Photograph: House of Commons

Nigel Farage has defended making another trip to the US, where he is speaking at an event alongside a leading far-right Austrian politician whose party has opposed sanctions against Russia.

The event on Friday evening in Chicago is the Reform leader’s third visit to the US in little more than two months since he was elected MP.

Farage is listed as the main speaker at a benefit event for the Heartland Institute, an Illinois-based rightwing thinktank which is a denier of human-created climate change. Its president, James Taylor, who is also speaking, has called climate change “a sham”. Tables at the dinner cost up to $50,000 (£38,000) each to reserve.

It has now emerged that another speaker listed at the dinner is Harald Vilimsky, a veteran figure in Austria’s far-right Freedom party, who leads the party’s representation in the European parliament.

In 2016, the Freedom party signed what was described as a cooperation pact with President Putin’s United Russia party. While the Austrian party says this is no longer in operation, it has been accused of sympathy with Russia.

However, the Freedom party has argued against sanctions on Russia, and Vilimisky has expressed opposition to the idea of Ukraine potentially joining the EU.

During the UK election, Farage faced criticism for his own views about Russia after he said that the EU and Nato “provoked” Moscow’s invasion of Ukraine by expanding eastwards.

Farage, who was elected to represent Clacton in Essex on 4 July, went to the Republican national convention in Milwaukee two weeks after the general election, and spoke at an event in Arizona in August, events his aides said had been booked long before he was elected.

Asked about the latest engagement, and Vilimsky’s presence as a fellow speaker, Farage told the Guardian: “It’s a conference with many guests! I wonder if other MPs have had holidays this year? These little trips count as mine.”

A spokesman for Mr Farage said: “Nigel told the people of Clacton that he would spend some time in America if elected. They gave him a majority of 8,405.”

Promoting the fundraising dinner, for its 40th anniversary, the Heartland Institute described Farage as “a leading voice in the fight for freedom and the architect of the new conservative movement in the UK and across Europe”.

Individual tickets cost from $199 each, with tables priced from $4,000 upwards. What is described as a “platinum table” for nine people, who will sit with Farage during the dinner, is listed on the institute’s website as having already sold for $50,000.

For the event in Arizona, Farage’s register of interests as an MP showed he has thus far been paid just under £12,000 as a “deposit”.

The Heartland Institute has been accused of promoting climate change denialism. In an article last October for the thinktank, Taylor argued that there “cannot be a climate crisis when temperatures are unusually cool”, saying “virtually every alarmist climate prediction has proven false” and that warmer temperatures “are a blessing, not a curse”.

Later this month, Farage is listed as a speaker at the Nomad Capitalist Summit, an event at a luxury hotel in Kuala Lumpur, Malaysia, described as “the world’s foremost gathering of global citizens discussing second citizenship, legal offshore tax strategies, international investing, and the Nomad Capitalist lifestyle”.

Jolyon Maugham, director of the Good Law Project, said: “He does know, Nigel Farage, doesn’t he, that the sea Clacton is on is not the Black Sea, or the Singapore Straits or the Pacific? I am starting to wonder whether to set up a crowdfunder for an atlas.”