Diplomatic ties with Taiwan have become a flashpoint in Central America, where Beijing is looking to deepen links.
Castro, who said during her election campaign in 2021 that she would switch ties to Beijing before her team backtracked, wrote on Twitter Tuesday night that she had instructed her foreign minister to begin the process of recognising China.
Central America and the Pacific have some of the last few countries to recognise Taiwan over China, and Beijing has been looking to deepen links with a region that the United States has long seen as within its sphere of influence. Nicaragua broke off diplomatic relations with Taiwan a year and a half ago.
With Honduras making the switch, Taiwan will be left with only 13 formal diplomatic allies around the world.
Beijing views democratic Taiwan as its own territory, with no right to state-to-state ties, a view the government in Taipei strongly rejects.
In 2019, several Pacific countries, including the Solomon Islands, switched allegiance to Beijing.