Taiwan has accused Beijing of offering Chinese-made Covid vaccines to pressure Paraguay to sever ties with the island.
Foreign Minister Joseph Wu claimed China had promised millions of doses for Paraguay which has been hit hard by the pandemic.
Beijing considers Taiwan to be a part of China and says it should unite with the Chinese mainland.
China has denied using vaccines to try and persuade Paraguay to change allegiance.
Paraguay is only one of a handful of countries that recognise the self-governing territory of Taiwan as a sovereign nation.
Speaking on Wednesday, Mr Wu accused China of "vaccine diplomacy".
"The Chinese government was very active in saying if the Paraguay government is willing to sever diplomatic ties with Taiwan, they will be able to get quite a few million vaccine doses from China," he added.
Mr Wu said Paraguayan President Mario Abdo Benítez had been put under pressure and Taiwan had asked other countries to help procure vaccines for Paraguay. India says it has sent 100,000 doses.
The country has also received 36,000 doses from AstraZeneca, 4,000 doses of the Russian Sputnik V vaccine and 20,000 of the Chinese Sinovac.
Last month Paraguay said unofficial brokers who claimed to have access to China's vaccines had offered a deal. However, Paraguay's foreign ministry said their links with China and its government had not been proven.
China's Foreign Ministry then denied the claims and said they were part of a "disinformation campaign originating in Taiwan".
Paraguay has reported 224,736 cases of Covid-19 and 4,522 deaths, according to data from Johns Hopkins University. Last month protests broke out in the country over the handling of the pandemic.
Only 15 countries officially recognise Taipei over Beijing. A number of allies are under pressure to change their allegiance. On Wednesday, Surangel Whipps, president of the South Pacific island nation of Palau, claimed he would often receive calls from Chinese officials in the run-up to elections last year. He is adamant that despite the pressure, he will remain tied to Taipei.
China has proposed that Taiwan be governed under a "one country, two systems" structure similar to Hong Kong.