WASHINGTON —Sen. Mary Landrieu led the questioning Tuesday on the impacts of proposed Homeland Security budget cuts on everything from domestic terrorism response resources after the Boston Marathon bombings to decreased funding for new U.S. Coast Guard vessels built in Louisiana.

Landrieu, D-La. and chairwoman of the Senate Appropriations Homeland Security Subcommittee, discussed the budget issues with Homeland Security Secretary Janet Napolitano during a hearing on the president’s budget proposal that decreases departmental funding by about $800 million, or 2.2 percent.

Napolitano said the White House administration is working with an “unprecedented” level of fiscal restraint in the wake of budget reductions and the automatic sequester budget cuts in place. But she insisted that support for the detection of terrorist threats and the responses to them will not suffer.

Although the FBI has faced some criticism for not identifying the Boston Marathon bombers as serious threats before last week’s attacks, Napolitano praised the response efforts.

“The response was swift, effective and, in many ways, will serve as a model for the future,” Napolitano said.

Landrieu asked about the efforts to identify early and catch “violent extremists.”

“We really don’t have a clear understanding of the path someone takes to really become (an extremist),” Napolitano said, but she argued that they do effectively rely on a “tips” system to identify people who are becoming radicalized and that response training exercises have proven effective.

Switching gears to Coast Guard and ports resources, Landrieu andSens. Thad Cochran, R-Miss., and Lisa Murkowski, R-Alaska, were all critical of decreased funding.

While Landrieu succeeded last month in securing $335 million for six new “fast-response cutter” ships for the U.S. Coast Guard, next year’s proposed budget only includes funding for two fast-response cutters and one national security cutter ship.

“It’s a tough, tough, tough budget,” Napolitano said.

Landrieu also complained about budget cuts in cybersecurity education and in ongoing delay problems at airports for international travel through customs. “I’m very sensitive to this,” Landrieu said, noting that Louisiana depends on tourism, including international tourists.

Overall though, Landrieu praised Homeland Security for its progress after one decade of existence. Anti-terrorism efforts are much stronger, she said, and the nation’s southern border is more secure, even though Republicans often argue otherwise. Landrieu also praised the gains made in the Federal Emergency Management Agency.