China urged the United States to focus on its domestic fight against deadly coronavirus Tuesday as it alleged Washington continues to violate its sovereignty.

“While China is helping others in our fight against the pandemic, the U.S. is sending aircraft and vessels frequently to the South China Sea, violating China’s sovereignty,” the country’s Foreign Ministry spokesperson Zhao Lijian told a news conference in Beijing.

China regards the entire South China Sea as its own and that has triggered tensions in the region. Taiwan, which China calls a “breakaway province,” has developed defense relations with Washington that has intensified tensions.

Read more: China urges US to prioritize domestic COVID-19 fight