The Taoiseach, Mr Ahern, has sent a letter to the German Chancellor, Mr Gerhard Schroder, to express, on behalf of the Government, "shock and sympathies on the tragic deaths" of the German passengers on board the Concorde.
"Our sympathies go out to those who have lost loved ones, to those who are still awaiting news of missing relatives and to all who are suffering as a result of the accident," he wrote.
Mr Ahern also wrote to the Prime Minister of France, Mr Lionel Jospin, expressing "deepest sympathies" on the crash of the Air France Concorde.
"Our condolences go to those who have lost loved ones, to those who are still awaiting news of missing relatives and to all who are suffering as a result of the accident.
"I would like to send our sincerest good wishes for the success of the rescue efforts and for the recovery of the injured," said Mr Ahern.
In Washington, President Clinton expressed his sorrow yesterday over the crash.
"I just heard the news of the crash of the Concorde outside Paris, and I wanted to extend the deepest condolences of the American people to the families of those who were lost," Mr Clinton said at a news conference called to announce the outcome of the Middle East peace talks at Camp David, Maryland.
The German Chancellor, Mr Schroder, is "shaken" by the crash, his spokeswoman said. He had cancelled an appointment he had for late yesterday in his home town of Hanover and was following news of the event, she added.
Mr Schroder expressed condolences for the families of the dead.
In Paris, the Prime Minister, Mr Jospin, said: "I have telephoned Chancellor Gehard Schroder and sent our condolences and let him know all our thoughts are with the families of those killed."
Queen Elizabeth, the British Prime Minister, Mr Blair, and the Conservative leader, Mr William Hague, offered their sympathy last night to the relatives of those killed. As the investigation into the disaster got under way, Queen Elizabeth sent messages of sympathy to the French President, Mr Jacques Chirac, and to Mr Schroder.
As soon as he was informed of the crash, Mr Blair wrote to Mr Chirac, Mr Jospin and the German Chancellor to express "shock and sympathy" on behalf of the British government.
Sending his condolences to the bereaved, Mr Hague said the crash was a "horrific event" and that the cause of the tragedy must be discovered as soon as possible.
Speaking a few hours after the crash, Mr Hague said: "Our thoughts and sympathies go out to the families in Germany and France who have lost friends and loved ones today. We need to find out what went wrong, and soon."