"It's our dominating theme today and will remain so over the weekend as bodies are recovered and we start to get a sense of the scale of the tragedy".
The EU's chief negotiator, Michel Barnier, has long argued that the initial talks should center on brokering deals on citizens' rights, money owed by the United Kingdom and the border between Northern Ireland and the Republic of Ireland.
"Our view is that withdrawal agreement and terms of the future relationship must be agreed alongside each other", said the spokesman.
"My clear view and I believe the view of the majority of people in Great Britain is we should be protecting jobs, protecting economic growth and protecting prosperity", Chancellor of the Exchequer Hammond said as he arrived for regular talks with his European Union counterparts in Luxembourg.
"I'm not going to give a blow by blow account of how we propose to take that discussion forward", he said.
The Brexit Department said in a statement that the UK's withdrawal and future ties are "intimately linked".
Speaking as he arrived for a meeting of European Union finance ministers in Luxembourg, he said: "As we go into that negotiation, my clear view - and I believe the view of the majority of people in Britain - is that we should prioritise protecting jobs, protecting economic growth and protecting prosperity as we enter those negotiations and take them forward". Her Conservative Party called such an arrangement "necessary" in its election manifesto.
Verhofstadt said Britain must urgently either confirm the positions she outlined in its March 29 letter triggering the two-year Brexit process, "or they open the game in another direction, that's their responsibility".
Foster's Democratic Unionist Party has been in talks with May's Conservatives after the prime minister's party failed to win a majority in a national election.
A spokesman for his Department for Exiting the European Union said Britain had been "crystal clear" about its approach.
Hammond, who may be in the vanguard of the shift, said in Luxembourg that he favors a "pragmatic" Brexit that safeguards jobs and the economy.