TAIPEI, Taiwan (AP) -- Taiwan has again rejected South Africa's demand that it move its representative office in the country from the capital, Pretoria, to the commercial center of Johannesburg.

Taiwan Foreign Ministry spokesperson Jeff Liu said at a news conference on Tuesday that the demand to move or shut the office entirely violated a 1997 agreement between the sides on the location of their mutual representative offices following the severing of formal diplomatic relations.

"Facing this kind of unreasonable demand, our side cannot grant our acceptance," Liu said.

South Africa maintains a liaison office in Taiwan's capital, Taipei, and the sides have a strong commercial relationship. Liu repeated Foreign Minister Lin Chia-lung's avowal at the legislature on Monday that Taiwan "was prepared for all eventualities" over the issue. The office is Taiwanese property and Taipei retains the right to determine its location and status, Lin and Liu said.

China, which claims Taiwan as its own territory that must be annexed by force if necessary, relentlessly seeks to minimize Taiwan's international representation, although the self-governing island republic maintains robust unofficial relations with the U.S. and other major nations.

South Africa confirmed last week that it had asked Taiwan to move its liaison office, in a demand seen purely as a concession to China, which has used its influence to keep Taiwan out of the United Nations and affiliated branches such as the World Health Organization, and limit its formal diplomatic partners to just 11 countries and the Vatican.

In addition to diplomatic and economic pressure, China has stepped up its military threats against Taiwan, most recently holding large-scale live-fire drills just off the Chinese coastal province of Fujian, which faces Taiwan.

South Africa's demand that Taiwan move its office has also drawn attention in the U.S. Congress, with Tennessee Republican Sen. Marsha Blackburn posting on the social platform X that "the United States should not tolerate this behavior from South Africa."

"I am calling on ... the Biden administration to make it clear that there will be consequences if South Africa works with the (Chinese Communist Party) to bully Taiwan," including removing South Africa from a key trade program, Blackburn said.

"The United States must not provide trade benefits to countries that prioritize China's influence over democratic partnerships," she added.