Washington (CNN) -- Just hours after an ISIS spokesman called on the group's foreign fighters to carry out attacks on coalition countries led by the United States in the battle against the terrorist group, a senior Obama administration official warned the international community is not prepared to respond to such threats. "We're not structured that way effectively right now" to respond to that kind of call, the official said. President Obama hopes to "galvanize" international efforts to deal with the foreign fighter threat during his trip to the United Nations General Assembly in New York this week. "It sends a very powerful signal that this is an item of the highest urgency," said a senior administration official, who described the danger posed by foreign fighters as "extremely worrying."
@highlight
ISIS has called on its foreign fighters to attack countries that join coalition led by U.S.
@highlight
Official: International community "not structured ... right now" to respond to such a threat
@highlight
At U.N. this week, Obama hopes to "galvanize" international efforts against ISIS
@highlight
Senior official calls danger posed by foreign fighters "extremely worrying"
The meeting will be chaired by Obama, marking only the second time he has presided over a @placeholder session during his time in office.