United Nations Secretary-General Ban Ki-moon says he is "deeply concerned" by Egypt's confirming the sentencing to death of deposed president Mohamed Morsi, and more than 90 others, in connection with a 2011 mass prison break.
"The United Nations is against the use of the death penalty in all circumstances," Ban's press office said in a statement Tuesday.
"The secretary-general is concerned that such verdicts, handed down after mass trials, may well have a negative impact on the prospects for long-term stability in Egypt."
The statement says Ban is urging Egyptian authorities to ensure that defendants can benefit from due process and guarantees of a fair trial.
The United States said it was "deeply troubled" by the sentences, which it described as politically motivated.
White House spokesman Josh Earnest said the United States is "concerned that the proceedings have been conducted in a way that is not only contrary to universal values but also damaging to the stability that all Egyptians deserve."
An Egyptian court on Tuesday confirmed the death sentence of former president Morsi, who was originally sentenced last month along with 100 others.
The same court also sentenced him to life in prison in a separate case involving charges of conspiring with foreign groups, including the Palestinian militant group Hamas.
Since his 2013 ouster led by then-army chief and current President Abdel Fattah el-Sissi, the Egyptian government has brought multiple charges against Morsi and the leaders of his banned Muslim Brotherhood amid a massive crackdown against the group.
Tuesday's rulings included a death sentence for Brotherhood leader Mohamed Badie and life in prison for other leaders.
The sentences can be appealed.