By PABLO GORONDI, Associated Press

BUDAPEST, Hungary (AP) — Russian President Vladimir Putin was in Hungary for the second time this year on Monday, attending the World Judo Championships in Budapest and discussing mutual energy interests with his Hungarian counterpart.

Putin, who made an official trip to Hungary in February, sat in a VIP box at the Laszlo Papp Budapest Sports Arena with Hungarian Prime Minister Viktor Orban and other officials.

Discussions between the two leaders centered on energy issues, including Russia's construction of new reactors for Hungary's Soviet-built nuclear power plant and Hungarian imports of natural gas from Russia.

Hungarian Foreign Minister Peter Szijjarto said the expansion of the power plant in Paks, in central Hungary, would begin next year, after what he said had been a 22-month delay while the European Union examined the project's compliance with EU rules.

"The procedures regarding the European Union have taken longer than expected and they have taken longer than they should have," Szijjarto said after dining with Orban and the Russian delegation. "The real construction work will start in January and nothing will stop the investment from now on."

Szijjarto also said that Bulgaria, Serbia and Hungary would upgrade parts of their natural gas pipelines to allow the transport of up to 10 billion cubic meters of Russian gas to the region by the end of 2019.

Hungarian opposition parties protested Putin's trip amid concerns that Orban has become too close to the Russian leader. Orban used to be highly critical of Russian influence in the region.

Activists from the Together party blew whistles as Putin's motorcade arrived at the arena and held up a banner in the stands reading "We Won't Be A Russian Colony" before police escorted them out of the building.

A few supporters of Momentum, a new party whose recent campaign led Budapest to withdraw its bid for the 2024 Olympic Games, donned Putin masks and wore T-shirts with the slogan "Let's go freedom of speech, let's go Hungarians."

Critics say the nuclear project is rife with corruption risks and increases Hungary's dependency on Moscow.

"Putin is looking for colonies in the former Soviet bloc, not allies," political activist Gabor Vago said. "Only Russia benefits from the nuclear deal, which ties Hungary for decades to an obsolete technology."

Russia has loaned Hungary 10 billion euros ($11.9 billion) for the nuclear development plan, an amount expected to cover about 80 percent of the costs.