Russian Foreign Minister Expected to Face Rebuke at U.N.

She added: “China’s stance on the relevant issues hasn’t changed,” and noted that China was one of the first countries to establish relations with all the “relevant countries” after the Soviet Union dissolved in 1991.

The recent rhetorical gyrations of Chinese diplomats — including Mr. Lu and Fu Cong, the Chinese ambassador to the European Union — suggest that Beijing is still struggling to strike a balance between courting European leaders and supporting Russia, with which it has declared a “no limits” partnership. The war in Ukraine has put Beijing in an awkward position: It has refused to condemn Russia’s invasion while also promising not to help Russia militarily in its war.

Mr. Lu sparked widespread consternation when asked on the French television station, TF1, whether Crimea, which was illegally annexed by Russia in 2014, was part of Ukraine under international law. He said that Crimea was Russian historically and had been handed over to Ukraine. He added: “Even these countries of the former Soviet Union do not have an effective status in international law, since there is no international agreement that would specify their status as sovereign countries.”

Fu Cong, China’s ambassador to the European Union, by contrast, told The New York Times in an interview this month that China did not recognize Russia’s annexation of Crimea or of parts of Ukraine’s eastern Donbas region, instead recognizing Ukraine within its internationally accepted borders, in line with Ms. Mao’s remarks on Monday.

But Mr. Fu also said that Beijing had not condemned the Russian invasion of Ukraine because it understood Russia’s claims about its being a defensive war against NATO encroachment, and because his government believes “the root causes are more complicated” than Western leaders say.

Still, Mr. Lu’s comments have caused confusion and anger in Ukraine and the European Union, especially among those countries of Eastern and Central Europe that were under Soviet rule or occupation. The Baltic nations, which were annexed by the Soviet Union after World War II, are especially sensitive to any suggestion that their sovereignty is under question.

At a meeting of E.U. foreign ministers in Luxembourg on Monday, Lithuania’s foreign minister, Gabrielius Landsbergis, said that the Chinese ambassadors would be asked to explain if the “Chinese position has changed on independence and to remind them that we’re not post-Soviet countries, but we’re the countries that were illegally occupied by Soviet Union.”

His Estonian counterpart, Margus Tsahkna, said that he wanted to know “why China has such a position or comments about the Baltic States,” which are all members of the European Union and NATO. Ms. Mao’s comments were not sufficient, he said. “I hope that there will be an explanation. We are not satisfied with that announcement.”

Josep Borrell Fontelles, the E.U. foreign policy chief, called Mr. Lu’s remarks “unacceptable,” as did the Czech foreign minister, Jan Lipavsky. Mr. Borrell said that Brussels, too, wanted a further explanation from Beijing.

Luxembourg’s foreign minister, Jean Asselborn, called Mr. Lu’s remarks a “blunder” and said efforts were being made to calm things down.

Mr. Lu has been a proponent of a style of tough talking sometimes called “wolf warrior” diplomacy. This will be the third time he has been summoned to the French Quai d’Orsay in the past three and a half years.

Christopher Buckley contributed reporting from Taipei, Taiwan. Olivia Wang contributed research.