"The EU is deeply concerned about the evolving humanitarian crisis and vast number of internally displaced people," the EU ministers said in a joint statement after talks in Brussels.
"The EU calls for an immediate ceasefire thereby providing for the establishment of full and unrestricted access" to allow aid to reach a jungle area of northern Sri Lanka as well enable traumatised civilians to leave.
Government forces are keeping up a major offensive there against the Liberation Tigers of Tamil Eelam (LTTE) guerrillas who have been hemmed into an increasingly smaller zone in the north.
The Tigers appealed Monday for international action to halt the offensive, but the island's military rejected any talk of a truce.
The EU foreign ministers urged the Sri Lankan government to ensure that camps for the displaced come up to international standards and can be independently monitored.
The foreign ministers also called on the Tamil Tigers to lay down their arms "and renounce terro