The foreign ministry “expressed its displeasure” with Trump’s order to bar Sudanese and citizens from six other Muslim-majority countries from entering the US for three months.
Koutsis is the most senior diplomat at the American embassy in Khartoum.
Trump signed an executive order on Friday temporarily prohibiting entry to the US to citizens from Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen and suspending the arrival of refugees.
Fatimah Abu Al-Qassem Al-Qash and businessman Amer Hamed al-Manufi were among the first Sudanese to be hit by the ban.
“We went through passport control at Khartoum airport and flew to Doha. But when we arrived there (on Saturday) we were detained with some Iranians and Iraqis,” Fatimah told AFP after her return home.
“A man who identified himself as an American employee told us that we cannot travel further,” she said, adding that she had a valid visa and had been planning to visit her brother in the state of Arizona.
Manufi, a dairy farmer, was on his way to Atlanta to attend a fair and sign business deals, when he was told he was not welcome in the United States.
“I run a group of companies… and we are also agents for international firms, including two American companies with which we have been working since 2009,” he said.
The US embassy in Khartoum posted on its website an announcement reiterating Trump’s executive order and stressing that visas would no longer be issued to citizens of the seven countries.
“If you are a national, or dual national, of one of these countries, please do not schedule a visa appointment or pay any visa fees at this time.
“If you already have an appointment scheduled, please do not attend your appointment as we will not be able to proceed with your visa interview.”
The words “do not attend” were in bold print.