Many Western countries have kept their diplomatic distance from Saudi Arabia's powerful Crown Prince Mohammed bin Salman, the king's favourite son, since Saudi dissident journalist Jamal Khashoggi was killed in Riyadh's consulate in Turkey in October. Khashoggi was a sharp critic of the heir apparent.
>> Read more: Mohammed bin Salman looks east, but worries about the west | Analysis
Mohammed's attendance at the weekend summit in Egypt would have put the Europeans in an awkward position as they try to strengthen cooperation with their Arab partners.
Egyptian state television showed President Abdel-Fattah al-Sissi Saturday welcoming the ageing Saudi monarch at Sharm el-Sheikh airport.
Strong attendance is expected at the two-day summit, which kicks off Sunday in the Red Sea resort city.
Romanian President Klaus Iohannis, whose country is currently holding the rotating European Union presidency, had earlier Saturday arrived in the city and met with al-Sissi, state media reported.
Streets of the city have been decorated with billboards carrying logos of the EU and the Arab League amid tight security.
Want to enjoy 'Zen' reading - with no ads and just the article? Subscribe todaySubscribe now