An unofficial delegation dispatched by the U.S. government arrived in Taipei by plane on Wednesday amid heightened tensions between the United States and China over the self-ruled island.

U.S. President Joe Biden sent former Sen. Chris Dodd and former Deputy Secretaries of State Richard Armitage and James Steinberg to Taiwan as a "personal sign" of his commitment to the Chinese-claimed island, Reuters reported earlier, citing a senior administration official.

Taiwan's Foreign Ministry said the unofficial U.S. delegation is scheduled to hold talks with President Tsai Ing-wen on Thursday. Tsai's office welcomed the delegates' visit and expressed its appreciation to the Biden administration.

Richard Armitage in Tokyo on June 8, 2018. (Kyodo)

The visit is tied to the 42nd anniversary of the enactment of the 1979 Taiwan Relations Act, under which the United States supplies the Chinese-claimed island with arms and spare parts to enable it to maintain sufficient self-defense capabilities, according to the Reuters report.

The dispatch follows "a long-standing bipartisan tradition of U.S. administrations sending high-level, unofficial delegations to Taiwan," the official was quoted as saying.

The official "waved off" a question about a possible coordination in timing between the delegation's visit and U.S. climate envoy John Kerry's trip to China from Wednesday, the report said.

The official said climate talks with China "shouldn't be linked with other areas of the relationship."

The visit comes just days after 25 Chinese warplanes entered Taiwan's air defense identification zone, the latest in a series of aerial incursions by China.

China's increasing pressure on the island, which Beijing regards as a renegade province awaiting reunification by force if necessary, has been a source of concern in the United States.

On Friday, U.S. State Department spokesman Ned Price said the department had issued new guidelines for U.S. government interaction with Taiwan counterparts, adding that the envisioned engagement would reflect "our deepening unofficial relationship."