Athens/Brussels, Ramadan 15, 1436, Jul 2, 2015, SPA -- Prime Minister Alexis Tsipras on Thursday urged Greeks to preserve "national unity" in the face of "temporary" difficulties, while the International Monetary Fund (IMF) said Athens would be dependent upon bailout aid for years to come, dpa reported. Tsipras has urged Greeks to opt for "no" on Sunday when they vote in a referendum he called on whether the country should accept reforms demanded by its creditors. But the IMF warned in a 23-page debt assessment that Greece's problems are far from over, arguing that Athens will need a further 50 billion euros (55 billion dollars) in funding to get through the end of 2018. -- SPA 21:26 LOCAL TIME 18:26 GMT www.spa.gov.sa/w