Europe's leaders have delivered a warning to the Egyptian authorities to answer their people with "political reform, not repression".
As protests continued in central Cairo, a statement agreed at a Brussels EU summit stopped short of calling on President Hosni Mubarak to step aside.
Instead it challenged the regime to honour the terms of a £150 million-a-year EU "Association Agreement", under which Egypt is committed to push through political and economic reforms in return for trade concessions and financial aid.
The EU statement came as Barack Obama's US administration said it was in talks with Egyptian officials about the possibility of Mr Mubarak resigning straight away, and the formation of an interim government before free and fair elections later this year.
Prime Minister David Cameron "played a significant role" in forging the summit declaration and was satisfied with the result, said a Downing Street spokesman.
The declaration emphasised the right to free and peaceful demonstration and said any attempt to restrict the free flow of information, including aggression and intimidation against journalists and "human rights defenders", was "unacceptable".
The text urged the Egyptian authorities "to meet the aspirations of the Egyptian people with political reform, not repression".
It said: "All parties should show restraint and avoid further violence and begin an orderly transition to a broad-based government. The European Council underlined that this transition process must start now."
The Foreign Office said its planned second chartered flight for Britons wishing to flee riot-hit Cairo would take off by 4pm on Saturday at the latest, and was scheduled to arrive at Gatwick Airport in West Sussex.
A spokesman said it had received 160 "expressions of interest" to board the 165 seater plane, with 100 people already confirmed on the flight.