But he said there had been longstanding concern that Iran was developing the more advanced centrifuge.

"This is an issue of longstanding concern between us," said one American official.

The prayer service grew out of a longstanding concern over the way the city has been treating homeless families.

But he has had to balance that goal with longstanding concerns about human rights abuses in the region.

The airport's neighbors have had longstanding concerns about noise and want to limit the number of commercial flights.

Posner is responding to a longstanding concern with the law and economics movement.

Defining the church's role in the political arena has been a longstanding concern for the Pope.

The turnaround on the part of three major companies is a powerful recognition of public health officials' longstanding concerns.

It may have been just the longstanding concern of how to walk to the podium without stumbling over one's feet.

The moral foundation of urban liberalism is its longstanding and ardent concern for the poor.