America is “dangerously vulnerable” to a potential terrorist attack, Senator Schumer says.

In an annual report released yesterday, Mr. Schumer gives the Bush administration a C- for its homeland security efforts, down from a C last year, and warns that the nation’s ports in particular require urgent action to prevent the smuggling of nuclear weapons into America.

“To beat terrorism you not only need a good offense, you need a good defense,” Mr. Schumer said yesterday at a press conference in Lower Manhattan. “Despite a national focus that was stated so strongly in the days after 9/11, Washington has left American vulnerable.”

Mr. Schumer’s report, which is based on assessments of homeland security by the Government Accountability Office and by independent observers, this year added a new category, energy security, that assesses efforts to protect infrastructure critical to producing and delivering energy, such as oil refineries and power plants. The report gave the Bush administration a C+ for energy security.

“While everyone’s been talking about high gas prices, high home heating oil prices, one attack would make the price go through the roof and really hurt our already damaged economy in very severe ways,” Mr. Schumer said. “Our nation’s precarious dependence on foreign oil would be made worse by any kind of domestic attack.”

The report also awarded a C+ for chemical plant security, a D for port security, a B- for nuclear security, a C for aviation security, a D for mass transit and truck security, a D for high-threat grant funding, and a C- for border security.

To beef up port security, Mr. Schumer said the government must quickly implement testing for nuclear materials on all incoming cargo containers at ports, citing Hong Kong’s security procedures as a model.

The senator said the report was the last his office would release, as its intent was to monitor the Bush administration’s response to security challenges in the aftermath of the attacks of September 11, 2001.