Foreign Ministry spokesman Lu Kang says any disputes between China and the US should be resolved through talks.
China responded angrily on Monday as Taiwan confirmed the first meeting in more than four decades between senior US and Taiwanese security officials.
Taiwan's national security chief David Lee met White House National Security Advisor John Bolton earlier this month, the island's foreign affairs ministry said in a statement on Saturday.
The official Central News Agency said the meeting was the first since the island and the United States ended formal diplomatic ties in 1979.
China considers Taiwan a wayward province, to be reclaimed by force if necessary, and the meeting angered Beijing which is already locked in a bitter trade war with Washington.
"China is extremely dissatisfied and resolutely opposed to this," Foreign Ministry spokesman Lu Kang told a daily news briefing, adding China was against any form of official exchanges between the United States and Taiwan.
The spokesman also said that any disputes between China and the United States should be resolved through talks.
The diplomatic ties between Beijing and Washington have become increasingly strained in recent weeks due to an escalating trade war, US support for Taiwan and China's muscular military posture in the South China Sea, where the United States also conducts freedom-of-navigation patrols.
The rare meeting will be viewed by Taiwan as a sign of support from the Trump administration. Tensions have also risen between Taipei and Beijing, which considers the democratically ruled island part of "one China".
The meeting took place during Lee's May 13 to 21 visit to the United States, Taiwan's brief statement said.
"During the trip, together with US government officials, Secretary-General Lee met with representatives from our diplomatic allies, reiterating support and commitment to a free and open Indo-Pacific region," the statement said.
Taiwan's foreign affairs ministry and the de facto US embassy in Taiwan declined to comment on Monday.
Beijing regularly calls Taiwan the most sensitive and important issue in ties with the United States, which has no formal ties with Taiwan but is the island's main source of arms.
The United States has in recent months increased the frequency of patrols through the strategic Taiwan Strait despite opposition from China.
China has been ramping up military and diplomatic pressure to assert its sovereignty over the island, conducting drills near Taiwan and snatching its few remaining diplomatic allies.
Earlier in May, the US House of Representatives backed legislation supporting Taiwan as members of the US Congress pushed for a sharper approach to relations with Beijing.
The Pentagon says Washington has sold Taipei more than $15 billion in arms since 2010.