Washington: The United States has canceled all visas contained by South Sudanese passports after a dispute over the country’s failure to accept the return of its nationals deported from the United States.

US President Donald Trump’s administration has taken aggressive steps to increase immigration enforcement, including repatriation of people considered to be in the United States illegally.

The administration has warned that countries that do not quickly take back their citizens will have consequences, including visa sanctions or customs.

South Sudan had failed to respect the principle that each country must accept the return of its citizens in a timely way when another country, including the United States, is trying to remove them, US State Secretary Marco Rubio said in a statement.

“With effect immediately, the US State Department takes actions to revoke all visas contained by South Sudanese passports and prevent further issuance to prevent entry into the United States of South Sudanese passport holders,” Rubio said.

“We will be prepared to review these actions when South Sudan is in full cooperation,” he added.

It’s time for South Sudan’s transitional government to “stop taking advantage of the United States,” Rubio said.

South Sudan’s Embassy in Washington did not immediately respond to a comment request.

African Union brokers arrived in South Sudan’s capital, Juba, this week for negotiations aimed at averting a fresh civil war in the country after its first vice president Riek Machar was placed under Husarrest last week.

South Sudan’s President Salva Kiir’s government has accused Machar – a long -standing rival who led rebel forces during a war in 2013-18 that killed hundreds of thousands – to try to arouse a new rebellion.

Machar’s detention followed weeks with battles in the northern upper Nile state between the military and the white army’s militia. Machar’s forces were allied with the White Army during the Civil War, but denies any current connections.

The war in 2013-18 was struggled largely along ethnic lines of warriors from the Dinka country’s largest group-there are behind Kiir and those from Nuer, the second largest group supporting Machar.