U.S. Homeland Security Secretary Michael Chertoff has defended federal grants that slash security funding to New York, Washington and other major cities.

The mayors of New York and Washington have denounced the new grant levels, announced Wednesday, that cut federal security assistance to their cities by 40 percent from the previous year. New York, which received a $207 million grant in 2005, will see funding drop to $124 million this year. Washington's security grant falls to $46 million, down from $77 million. Such funds have been used to boost vigilance of landmarks and high-risk targets, purchase equipment, and improve the training and capabilities of emergency responders in the event of a terrorist attack or a similar catastrophe.

Responding to criticism over the funding levels, Secretary Chertoff says New York's 2006 grant is roughly equivalent to the average funding the city has received in recent years. Speaking at the Brookings Institution, a Washington-based public policy organization, Chertoff said it is misleading to compare this year's funding with 2005, when the grant more than quadrupled from the previous year.

"We have consistently ranked New York as the number-one risk locality in the country," said Mr. Chertoff.  "And for that reason, over the past four years of just this single program, we have awarded more than $500 million to New York. That is more than twice the money given to the next-highest ranked city, which is Los Angeles."

Chertoff also noted that, in an interconnected nation, boosting security in one area can have a positive impact elsewhere. He said, for instance, it is in New York's interest to protect power plants outside the city that feed the power grid on which the city relies.

Nevertheless, Chertoff did acknowledge that the overall 2006 budget for federal security grants is lower than it was last year. He said the Department of Homeland Security has tough choices to make in deciding how to allocate limited resources.

"We cannot protect every single person at every moment at every place against every threat," he explained.  "What we have to do is manage the risk. And that means we have to evaluate consequence, vulnerability and threat in order to determine what is the most cost-effective way of maximizing security. And that means that there are going to be some elements of security that will not necessarily get full coverage."

Chertoff said much work remains to be done in protecting the United States from terrorists and other threats.  For example, he said his department aims to boost port and railroad security in an unobtrusive way that does not impede the economy.

He also noted that June 1 marked the official beginning of the Atlantic hurricane season. Chertoff said, at present, the United States is better prepared to deal with natural disasters than it was last year, when the initial federal response to the devastation caused by Hurricane Katrina in New Orleans was almost-universally criticized as lacking.