Addressing the General Assembly, Vice President Han Zheng repeated Beijing’s stance that Taiwan -- around which the communist mainland has staged repeated military exercises -- constitutes an “inalienable part” of China.
“No one should ever underestimate the firm resolve, strong will and the power of the Chinese people to safeguard their sovereignty and territorial integrity,” he said.
“Realizing China’s complete reunification is a shared aspiration of all the sons and daughters of the Chinese nation,” he said.
“We will continue to strive for peaceful reunification with the greatest sincerity and the utmost effort.”
Nearly all countries recognize Beijing rather than Taipei but the United States has a strong unofficial relationship with Taiwan, to which it provides weapons to ensure its self-defense.
Some US officials have voiced concern that China is stepping up preparations to seize the island by force, especially if Taiwan makes moves to declare its independence formally.
Experts say that China has been reviewing lessons from Ukraine, which Russia has failed to seize a year and a half after invading.
China is allied with Russia but has stopped short of providing large amounts of military support to Moscow.
Han said that China wanted a “cessation of hostilities and resumption of peace talks” on Ukraine.
“China supports all efforts that are conducive to the peaceful resolution of the Ukraine crisis, and stands ready to continue playing a constructive role for the early attainment of peace,” he said.
Han earlier in the week met on the sidelines of the General Assembly with US Secretary of State Antony Blinken, the latest effort by the two powers to manage their wide-ranging tensions.