BUDAPEST: Ambassadors of NATO member states and Sweden met in Budapest on Thursday to discuss their growing concern about Hungary's deepening relations with Russia, the US embassy told AFP.

Prime Minister Viktor Orban maintained close ties with the Kremlin even after Russian President Vladimir Putin launched the February 2022 invasion of Ukraine.

The two leaders met on Tuesday in Beijing for the first time since Moscow started its offensive.

This was the main topic of the ambassadors' meeting on Thursday, a spokesman from the US embassy told AFP.

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"It is worrying that Hungary has chosen to engage with Putin in this way," America's envoy to Budapest David Pressman told US-funded Radio Free Europe, which first reported on the ambassadors' meeting.

"As is the language used by the prime minister to describe Putin's war in Ukraine. Both deserved to be discussed."

"We are all concerned that the Hungarian prime minister has met President Putin while Russia is at war with Ukraine as an aggressor," the ambassador emphasised.

"If we have legitimate security concerns, we will communicate those concerns to our allies and expect them to take them seriously," he added.

Pressman has already lambasted Orban for standing with "a man whose forces are responsible for crimes against humanity in Ukraine." The Hungarian government rejected the criticism.

"The US ambassador is not competent to determine Hungarian foreign policy, because that is the task of the Hungarian government," Orban's chief of staff Gergely Gulyas told Hungarian broadcaster ATV.