KUWAIT CITY - The third edition of international donors' conference for Syria opened Tuesday in Kuwait City, with the UN appealing for 8.4 billion U.S. dollars to fund aid programs in 2015.

Speaking at the conference, UN Secretary General Ban Ki-moon said the Syrian crisis is the "worst humanitarian crisis of our time. The Syrians are not asking for sympathy, they are asking for help."

On behalf of the host country, Emir Sheikh Sabah Al-Ahmad Al-Jaber Al-Sabah pledged 500 million U.S. dollars to Syrian refugees. He also called the Syrian crisis "the biggest humanitarian catastrophe in the modern history of mankind."

Representatives from 78 countries and 40 international organizations came to the gulf state to try to meet the UN's appeal, which was significantly higher than the 3.9 billion U.S. dollars raised in the previous two conferences.

In a non-government organization fundraiser held Monday, 506 million U.S. dollars were contributed by Kuwaiti and international NGOs.

The Syrian crisis have raged on for more than four years, during which it killed more than 220,000 people and left 12 million homeless, among which 3.7 million were driven out of the country.

A delegate of the Iranian nuclear negotiations team said there is the possibility of working out an agreement on basic issues, Iranian media reported Tuesday.  (Xinhua)