Philippine Secretary of Foreign Affairs Teodoro Locsin Jr. slammed China with decidedly undiplomatic language on Twitter Monday, suggesting the Asian giant “get the fuck out” as the two countries engage in a war of words over the South China Sea.

Locsin in the tweet accused China of straining its “friendship” with the Philippines. The foreign affairs secretary has been a vocal critic of China in the administration of Philippine President Rodrigo Duterte, who sought closer ties with Beijing after taking office in 2016.

In response to criticism of his rhetoric made by other Twitter users, Locsin said the “usual suave diplomatic speak gets nothing done.”

The Philippines and China have for years contested overlapping territorial claims in the South China Sea, a resource-rich waterway with a total area of about 1.4 million square miles where trillions in dollars of global trade pass. Beijing has in the past year appeared more assertive in the disputed waters.

Locsin’s Monday tweet followed a statement by the Philippine foreign affairs department, which protested the “illegal presence” of Chinese vessels in parts of the South China Sea that are internationally recognized as belonging to the Philippines.