China threatened to take counter-measures against the U.S. after Secretary of State Mike PompeoMichael (Mike) Richard PompeoGOP lawmakers call for new sanctions on senior Chinese officialsDemocrats to probe Trump’s replacement of top Transportation Dept. watchdogTrump tries to soothe anxious GOP senatorsMORE congratulated Taiwans president on starting a second term in office.

On Pompeos congratulation to Tsai Ing-wen on her inauguration, we express strong indignation and condemnation. China will take necessary counter-measures, and the consequences will be borne by the US side, said Lijian Zhao, a spokesperson for the Chinese Foreign Ministry.

On Pompeos congratulation to Tsai Ing-wen on her inauguration, we express strong indignation and condemnation. China will take necessary counter-measures, and the consequences will be borne by the US side. pic.twitter.com/I09FVPJM80

Lijian Zhao (@zlj517) May 20, 2020

Chinas Ministry of Defense added in a statement that Pompeos remarks seriously violated the one-China policy and that Taiwan is an inalienable part of China.

The Wednesday warning came after Pompeo touted the relationship between Washington and Taipei under the leadership of President Tsai Ing-wen.

Congratulations to Dr. Tsai Ing-wen on the commencement of your second-term as Taiwans President. Taiwans vibrant democracy is an inspiration to the region and the world. With President Tsai at the helm, our partnership with Taiwan will continue to flourish, Pompeo tweeted Tuesday.

Congratulations to Dr. Tsai Ing-wen on the commencement of your second-term as Taiwans President. Taiwans vibrant democracy is an inspiration to the region and the world. With President Tsai at the helm, our partnership with Taiwan will continue to flourish.

Secretary Pompeo (@SecPompeo) May 19, 2020

The threat from Beijing comes as relations between the U.S. and China continue to deteriorate, with both sides accusing the other of being responsible for the coronavirus pandemic. President TrumpDonald John TrumpPro-Trump outside groups raise .8 million in AprilBiden wins Oregon primaryGraham to release report on his probe into Russia investigation before electionMORE and lawmakers in Washington have accused Beijing of initially concealing the seriousness of the outbreak in Wuhan, China, allowing the disease to accelerate, while some Chinese officials have spread the conspiracy theory that the pandemic began in the U.S.

The ties between the U.S and Taiwan, which China views as its own territory, has also emerged as a flashpoint in the contentious relationship in recent months.

The U.S. has no official relations with Taiwan, though it has boosted arms sales to the island and passed a string of laws to blunt pressure on the territory from mainland China.

Trump signed legislation in March that requires the State Department to provide Congress with a report on steps to strengthen Taiwans diplomatic relations and mandates the U.S. alter engagement with countries that undercut the islands security.

The law led to a rebuke from Beijing, which urged the U.S. to correct its mistakes and warned of a resolute strike back by China.

Beijing views the warming of relations as a breach of the one-China policy. The Trump administration officially supports that policy, whereby the U.S. agrees to only deal with China for diplomatic affairs with territories it claims as its own.