WASHINGTON, April 5 (Aljazeera) - United States House Speaker Kevin McCarthy has met Taiwan’s President Tsai Ing-wen in his home state of California, a historic visit that has already sparked condemnation from China, which claims the self-ruled democracy as its own.

The two leaders sat down together at the Ronald Reagan Presidential Library in Simi Valley, approximately 55 kilometres (34 miles) from Los Angeles.

The closed-door meeting makes McCarthy the highest-ranking official to meet a Taiwanese president on US soil since 1979, the year Washington established diplomatic relations with the People’s Republic of China.

McCarthy called Tsai “a great friend to America” and added: “I am optimistic we will continue to find ways for the people of America and Taiwan to work together to promote economic freedom, democracy, peace and stability.”

Tsai thanked McCarthy for his hospitality, calling it warm like the California sunshine, and also thanked the rest of the congressional delegation, saying: “I am so pleased.”

Beijing had already criticised Tsai’s stopovers in the US as part of a visit to diplomatic allies Guatemala and Belize and swiftly condemned the the meeting between McCarthy and Tsai who it frames as a “separatist” bent on securing Taiwan independence.

“In response to the egregiously wrong action taken by the United States and Taiwan, China will take strong and resolute measures to defend our sovereignty and territorial integrity,” the foreign ministry said in a statement released on Thursday in Beijing. The defence ministry said that China’s army would be on “high alert”.