Egypt's justice minister said on Tuesday he had sent back a letter from the U.S. ambassador that asked for an end to a travel ban on Americans being investigated for alleged illegal funding of pro-democracy groups.
U.S. officials have warned the escalating dispute could imperil some $1.3 billion in annual U.S. aid to Egypt's military, and Republican Senator John McCain said on Tuesday he planned to raise the issue with a visiting Egyptian delegation.
In Cairo, Justice Minister Adel Abdelhamid Abdallah said he returned the U.S. embassy letter, highlighting strains between Washington and its long-standing Arab ally since the overthrow last year of Egyptian President Hosni Mubarak in a popular uprising.
Washington said several U.S. citizens working for civil society groups were banned from leaving Egypt and took refuge at its embassy in Cairo after the non-governmental organisations were raided by the military-led Egyptian authorities.
Abdallah said U.S. Ambassador Anne Patterson's written request to lift the travel ban was sent to his home and he returned it to the U.S. embassy because it should have been sent to the investigating judges.
"In it were the names of the people banned from travel and it was asking for a cancellation of this decision to be considered, as their constitutional right," he said.
"I spoke to the embassy and I returned this letter and told them that this letter should be sent to the investigating judges and not to the minister of justice," he said.
Abdallah said only those concerned by the travel ban or their representatives were entitled to send such a letter.
In Washington, the State Department confirmed that Patterson sent the letter, describing it as one of a number of attempts to raise the travel ban issue with Egyptian authorities.
"It was the justice minister's prerogative to send this letter back. We're going to continue to engage on this," State Department spokesman Mark Toner told a news briefing.
Toner said Washington would continue to press Egypt to allow the NGO staffers to leave.
"We believe that it's important that they be allowed to travel freely and that the conditions that have been placed on them are unfair," Toner said.
Parliament speaker Mohamed Saad al-Katatni, a leading figure in Egypt's Muslim Brotherhood which now dominates the assembly's lower house, said Patterson's request was "interference by the American embassy that we do not accept."
The U.S. embassy in Cairo had no comment.
U.S. officials said they will raise the NGO issue when a senior Egyptian military delegation visits Washington this week.
The delegation of generals is expected to meet with officials at the State Department and Pentagon. McCain said he planned to meet the Egyptian delegation as well; an aide to McCain said this meeting would take place next week.