The Government has banned US aircraft from using Irish airports to ship weapons to Israel.
"In light of the changing situation since the conflict has escalated, any request to transport weapons through Shannon for use in that conflict will be refused. Those flights will not be allowed land in Ireland," said a Foreign Affairs official.
"The Minister has made his desire for a ceasefire clear on many occasions so this action is entirely consistent with that. It has come about since the campaign began," a spokeswoman said.
The Taoiseach said yesterday he was "shocked and appalled" at the deaths of up to 60 Lebanese civilians in an Israeli air strike in the village of Qana.
In a statement, Mr Ahern said the incident "strongly underlines the clear message the Government has been giving out which is that an immediate ceasefire on all sides is urgently necessary.
"Military actions are only making a solution more difficult."
The Taoiseach said the Minister for Foreign Affairs would be making Ireland's views known at a meeting of European Union foreign ministers in Brussels next Tuesday.