Hamdeen Sabahi, a leader of the National Salvation Front (NSF), said late Thursday that he and ElBaradei objected to Washington's call for the opposition to reconsider its boycott of Egypt's parliamentary election in April.

"I received an invitation and turned it down, and Dr ElBaradei received an invitation and he turned it down," Sabahi said in an interview with ONTV television channel.

"We want to send a message that we reject American pressure," Sabahi added.

An aide of another NSF leader, former foreign minister Amr Mussa, said Mussa would also not attend a meeting with Kerry at which the opposition could be pressed to reconsider its boycott.

"We see that there is not way we can participate in the election, this is an NSF decision, and the unity of the NSF is our number one priority," the aide told AFP, on condition of anonymity.

He said Mussa would instead send a representative.

Kerry is expected in Egypt over the weekend, but a US State department official could not confirm his schedule, or whether Kerry expected to meet with Sabahi and ElBaradei.

"The secretary is looking forward to... his visit to Cairo to see what we can do to help the Egyptian people in terms of their democratic aspirations and looking at some of the economic challenges they have," State Department deputy acting spokesman Patrick Ventrell said.

"We're a friend of the Egyptian people, and he looks forward to meeting a variety of Egyptian interlocutors from a variety of walks of life."

The opposition has sought to ratchet the pressure on Islamist President Mohamed Morsi with a combination of street protests and a boycott of the election, to be held over three months.

The NSF had demanded guarantees that the election will be transparent as a condition to participate.

It has complained of what it sees as US support for Morsi, whom some NSF members backed in last June's election against ousted leader Hosni Mubarak's last prime minister, Ahmed Shafiq.

But they now accuse Morsi of having betrayed the values of the uprising which overthrew Mubarak in early 2011 and having sidelined liberals and Christians since he took power.

US President Barack Obama last week told Morsi in a phone conversation that he welcomed his "commitment" to represent all Egyptians but encouraged him and the opposition to find common ground.

Copyright AFP (Agence France-Presse), 2013