(ANSA-AFP) - WARSAW, AUG 6 - Nationalist historian Karol Nawrocki was sworn in as Poland's new president on Wednesday following his victory in a June 1 election that dealt a major blow to the pro-EU government. Nawrocki, 42, a supporter of US President Donald Trump, took the oath of office in front of Polish lawmakers to begin his five-year mandate, AFP reporters saw. Nawrocki, who was sworn in as Poland's new president on Wednesday, is a former amateur boxer with a particular interest in the criminal underworld. The 42-year-old Nawrocki won a June 1 election with the support of the populist right-wing Law and Justice (PiS) party, which governed Poland from 2015 to 2023. Nawrocki campaigned under the slogan "Poland first, Poles first". While he has pledged to continue Poland's support for neighbouring Ukraine against Russia's invasion, he has denounced the benefits given to war refugees. He said in a campaign video in April that "social benefits will be above all for Poles" and that "in queues for doctors and clinics, Polish citizens must have priority". In May, he claimed Ukraine "has not shown gratitude for what Poles have done" and accused President Volodymyr Zelensky of "insolence". He opposes Ukraine's bid to join NATO. After speaking with Nawrocki last week, Zelensky said he looked forward to working together with the Polish leader. (ANSA-AFP).