Furious about a visit to self-ruled Taiwan last week by U.S. House of Representatives Speaker Nancy Pelosi, China had earlier extended its largest-ever exercises around the island it claims as its own beyond the four days originally scheduled.
China's military said on Wednesday it had "completed various tasks" around Taiwan but would conduct regular patrols, signalling a possible end to days of war games but also that Beijing would maintain pressure on the island.
Last week's Chinese exercises included launches of ballistic missiles, some of which flew over the island's capital of Taipei, and simulated sea and air attacks in surrounding skies and waters.
Several Chinese navy ships were still conducting missions off Taiwan's east coast and near Japan's Yonaguni island, the source familiar with the security planning in the areas near Taiwan said.
Yonaguni is the Japanese island closest to Taiwan, about 100 km (62 miles) off Taiwan.
Several Chinese fighter jets briefly crossed the unofficial buffer separating China and Taiwan in the strait earlier on Thursday, the person added.
China's military did not make any new comment on its military activity around Taiwan on Thursday.
However, the two sides continued their war of words, with Taiwan reiterating a rejection of China's proposed "one country, two systems" model for bringing the island under Beijing's control.
Only Taiwan's people could decide its future, the spokeswoman for Taiwan's foreign ministry, Joanne Ou, told a news conference in Taipei.
China was using Pelosi's visit to Taipei as an "excuse to create a new normality to intimidate Taiwan's people", Ou added.
In Beijing, Chinese foreign ministry spokesman Wang Wenbin said that "achieving the complete reunification of the motherland" was an unstoppable historical trend.
"We are willing to create a wide space for peaceful reunification, but we will never leave any room for all forms of secessionist activities for Taiwan independence."
China says its relations with Taiwan are an internal matter and it reserves the right to bring the island under its control, by force if necessary.
Taiwan has lived under the threat of Chinese invasion since 1949 when the defeated Republic of China nationalist government fled to the island after Mao Zedong's Communist Party won a civil war.
(Reporting By Yimou Lee; Additional reporting by Martin Pollard in Beijing; Writing by Ben Blanchard; Editing by Raissa Kasolowsky, Robert Birsel)
