Taiwan's national security chief David Lee met White House security adviser John Bolton this month, the island's foreign affairs ministry said on Saturday.

The official Central News Agency said the meeting was the first since the island and the US ended formal diplomatic ties in 1979.

China considers Taiwan a renegade province, to be reclaimed by force if necessary, and the meeting is likely to anger Beijing further.

The diplomatic temperature has risen in recent weeks amid an escalating trade war, US sanctions and China's increasingly muscular military posture in the South China Sea, where the US conducts freedom of navigation patrols.

The rare meeting will be viewed by Taiwan as a sign of support from the Trump administration, with tensions also rising between Taipei and Beijing.

The meeting reportedly took place during Lee's May 13-21 visit to the US.

"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.

Beijing regularly calls Taiwan the most sensitive and important issue in ties with the US, which has no formal Taiwan ties but is the island's main arms source.

The US 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, including conducting drills near Taiwan.

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 $US15 billion ($A22 billion) in arms since 2010.

Australian Associated Press