Opinion polls show the hardline former party leader is unlikely to win the presidency, but his views are influential within the Finns Party, which is part of the right-wing government that took office in June.
Delegates at the weekend conference discussed the party's EU stance in light of the Ukraine war and its governing alliance with pro-EU allies.
The Finns Party backed the country joining NATO this year.
The Finns Party congress also rejected the EU's proposed Nature Restoration Law, with Tavio calling it "a sad example of the acceleration of the EU's dictatorial policy under the guise of climate change".
The Finns Party has suffered two setbacks in recent weeks.
Persons:
Jussi Halla, Anne Kauranen HELSINKI, Party's Jussi Halla, aho, Halla, Ville Tavio, Vilhelm Junnila, Riikka Purra, Anne Kauranen, Justyna Pawlak, Hugh Lawson, Helen Popper Our
Organizations:
REUTERS, European Union, Saturday ., Finns Party, EU, Reuters, NATO, Foreign Trade, Restoration, Thomson
Locations:
Helsinki, Finland, Ukraine, EU, Western Europe, Europe, Halla