US official said Washington believed the aircraft, which is an Il-20 turbo-prop plane used for electronic reconnaissance, was inadvertently shot down by Moscow's ally, the Syrian government.
China claims Taiwan as its territory, and says the democratic island has no right to formal ties with any country.
The Dominican Republic severed ties with Taiwan and switched its allegiance to China on Tuesday, in another diplomatic blow to the self-ruled island, which accused the Caribbean nation of accepting false promises of aid from Beijing.
The Sri Lanka Freedom Party, formerly an ally of Prime Minister Ranil Wickremesinghe's United National Party, has confirmed that it will vote against the UNP.
Kim Jong-un has visited Pyongyang's ally Beijing for the first time, ahead of proposed summits with Seoul and Washington.
During the visit from Sunday to Wednesday, Kim has held talks with Xi Jinping in Beijing, where the Chinese president hosted a banquet to welcome the North Korean leader and his wife Ri Sol Ju,
Saudi forces had intercepted seven missiles on Sunday in a deadly escalation that coincided with the third anniversary of the coalition's intervention in Yemen.