The United States last weekend deported Chinese nationals who attempted to illegally enter the U.S., the Department of Homeland Security announced on Tuesday.

The weekend charter flight was the largest since 2018, and DHS is working with China’s Ministry of Public Security and National Immigration Administration on additional removal flights.

According to DHS, the United States and China are collaborating to minimize illegal immigration and address human trafficking issues.

DHS has been responsible for more than 120 international repatriation flights to more than 20 countries since President Joe Biden imposed toughened border controls on June 4, according to a statement from the U.S. diplomatic mission in China.

The challenge of acquiring U.S. visas combined with the economic impacts of China’s COVID-19 lockdowns contributed to a notable rise in Chinese nationals arriving at the U.S.-Mexico border

Nearly 56,000 Chinese migrants have been encountered at both the Southwest border with Mexico and the northern border with Canada crossing both between and at ports of entry in the 2024 fiscal year through May, Reuters reported citing U.S. government data. That is more than the 52,700 that crossed in the entire 2023 fiscal year that ended in October.

In August 2022, China ceased its cooperation with the United States on repatriating Chinese migrants in retaliation for the visit to Taiwan by then-Speaker of the House Nancy Pelosi. However, as more crossings have been reported at the U.S. southern border, China has resumed its cooperation.

“We will continue to enforce our immigration laws and remove individuals without a legal basis to remain in the United States,” DHS Secretary Alejandro Mayorkas said in a statement.

Some information for this report was provided by Reuters.