A year after President Vladimir Putin committed a "breach of civilization," the conference is faced with the question of how the "rules-based international order" can be respected, said the event's chairman, Christoph Heusgen.

"In [the] future, will there be an order where the strength of law dominates? Or will there be an order in which the law of the strongest prevails?" he asked at a news conference.

The question of "how to deal with people, political leaders, who do not respect the rule of law" will be on the agenda, he said.

U.S.-China tensions are likely to feature prominently at the gathering in the German city in the state of Bavaria, with ties having nosedived since Washington shot down an alleged Chinese spy balloon in early February.

Beijing has insisted it was for civilian purposes and Monday hit back, accusing the United States of flying balloons over its territory — a claim swiftly denied by Washington.

FILE - In this Feb. 24, 2019, file photo, U.S. fighter aircraft F-16 perform aerobatic maneuvers on the last day of Aero India 2019 at Yelahanka air base in Bangalore, India.

Heusgen said he did not think that Wang would use remarks at the event to say "sorry, that was our spy balloon that flew over."

But he added that "I do hope that there will be talks... on the sidelines. I have already pointed out that we have a high-ranking American delegation" attending.

Relations between the world's two biggest economies have deteriorated in recent years over issues ranging from human rights in Hong Kong to economic policy and the treatment of the Muslim Uyghur minority in Xinjiang. (AFP via VOA)