Hungarian Prime Minister Viktor Orban speaks to media after casting his ballots during the general parliamentary elections on April 3, 2022 in Budapest, Hungary.Hungarian Prime Minister Viktor Orban speaks to media after casting his ballots during the general parliamentary elections on April 3, 2022 in Budapest, Hungary.

Hungary's nationalist Prime Minister Viktor Orban declared victory in Sunday's nationwide election, with partial results showing his Fidesz party leading the vote by a wide margin.

With Orban seeking a fourth consecutive term in office, preliminary results showed his party was set to control 135 seats of the 199-seat Parliament, comfortably ahead of the opposition alliance United for Hungary, which was set to gain 57 seats after 70% of the votes had been counted.

The election had been predicted to be closer than in previous years, but Fidesz still held a lead in the polls.

The most pro-Kremlin leader of the 27 nations of the European Union is Orban. He is the longest-serving leader since the fall of communism in 1989 and has been a thorn in the side of the European Union.

According to a translation by The Associated Press, Orban told his supporters that they won a victory so big that they could see it from the moon. Shortly after Orban's speech, Peter Marki-Zay admitted defeat.

The electoral campaign of Orban's Fidesz party was challenged because of his close relationship with Putin.

There have been commercial and energy deals between the two nations. In the last ten years, Hungary's imports of Russian natural gas have gone up from a low in 2010 to a high in 2019. Russia supplies Hungary with 85% of its gas and 64% of its oil.

Hungary became the first EU nation to buy a vaccine that wasn't approved by European regulators.

In the wake of Russia's invasion of Ukraine, Orban has sought to downplay his ties to Putin. Hungary must stay out of this conflict according to his messaging.

Hungary will welcome Ukrainian refugees and is in favor of Ukraine's application to join the EU. The sanctions against the Russian economy were approved by the other EU member states.

Hungary is a NATO member and is willing to host troops from the military alliance on its territory. The direct transit of lethal weapons to Ukraine via Hungary has been banned, but it has rejected any energy sanctions on Moscow.

In 2004, Hungary joined the EU and has been at odds with it ever since. The former communist state has been criticized for trying to exert its influence over independent institutions.

His party Fidesz still has strict control over state media, and previous election campaigns have been based on an anti-immigration and protectionist message. The country built a fence on its southern border during the European migration crisis.

Whoever wins on Sunday will have to deal with a number of challenges, including slowing economic growth, soaring inflation, and hundreds of thousands of refugees entering the country from Ukraine, according to Andrius Tursa, a Central and Eastern Europe advisor at Teneo.

The war in Ukraine has presented mounting economic and humanitarian challenges to the European Commission and they need to unblocked the country's access to the EU Recovery and Resilience Facility.

At the same time, the EC might be more reluctant to invoke the rule of law mechanism against Hungary and Poland until the war in Ukraine ends.

CNBC contributed to this article.