The United Nations is struggling to keep its peacekeeping missions staffed and supplied as the world endures an unprecedented combination of crises, U.N. Secretary-General Ban Ki-moon said Tuesday as he opened a two-day visit to Ireland.

"We are living through an era like no other. There are multiple crises: a food crisis, fuel crisis, flu crisis and financial crisis," Ban told an invited audience at the Dublin Castle conference center in between meetings with the president and prime minister of Ireland.

"Each is a crisis we have not seen for many years, even generations. But this time they are hitting the world all at once. We have never seen any era when we have been hit by all these multiple crises at the one time," Ban said.

He said U.N. donor nations were being compelled to cut their support in money, soldiers and other resources at a moment when the world's conflict zones need more support, not less.

"Peacekeeping has experienced serious setbacks. Today we face mounting difficulties in getting enough troops, the right equipment and adequate logistical support. This supply has not kept pace with demand," he said.

Ban said the United Nations employs 78,000 military personnel, 11,000 police and 23,000 civil servants in 16 peacekeeping operations and 27 other political missions in the world's trouble spots — but needed much more help to do its job properly in lands wracked by fighting, famine and poverty.

He said achieving U.N. goals increasingly would mean building up the capabilities of regional peacekeeping players, including the European Union and the African Union.

In comments aimed at domestic Irish opinion, Ban said Ireland should feel comfortable committing troops into European Union-organized peacekeeping forces. Officially neutral Ireland permits its forces to take part in missions only if they have a United Nations mandate, and a sizable minority of opinion opposes military cooperation in any other organizations even if they operate under a U.N. mandate.

"Let me assure you that Ireland's participation in EU military and civilian missions is fully compatible with its traditional support of the United Nations," he said. "This is not a zero-sum game in which more support for one institution means less for the other. We are in this together."

Later, Ban had a working lunch with Prime Minister Brian Cowen.

Ban's visit coincides with Ireland's worst recession since the 1930s, with a swelling budget deficit and unemployment lines.

Ireland, traditionally one of the strongest per-capita contributors to U.N. budgets, has been forced to slash its spending on U.N. work and other overseas aid by nearly half over the past year. Ireland's biggest current contribution is 450 troops in a U.N. force protecting civilians and aid workers along Chad's border with the Darfur region of Sudan.