Sen. Dianne Feinstein (D-Calif.) said she hoped that the president will decide on a strategy against the Islamic State that encourages a coalition with Arab nations. (J. Scott Applewhite/Associated Press)

Senate Intelligence Committee Chairman Dianne Feinstein (D-Calif.) on Sunday suggested that President Obama should be more decisive in dealing with the Islamic State.

"I think I've learned one thing about this president, and that is: He's very cautious — maybe in this instance too cautious," the senator said on NBC's "Meet the Press."

Feinstein added that the State Department and other agencies are putting together plans for addressing the threat posed by the Islamic State, saying she hopes the president will decide on a strategy that encourages a coalition with Arab nations.

"Jordan's at jeopardy, Lebanon's at jeopardy ... and other countries are in jeopardy," she said. "So there is good reason for people to come together now and begin to approach this as a very real threat that it in fact is."

Feinstein also acknowledged that Obama's description of the Islamic State in January as a "JV team" was inaccurate. "I think it's a major varsity team," she said, adding, "I see nothing that compares with its viciousness."

The senator also suggested that the United States was caught off guard by the Islamic State's capabilities and its rapid advances in Iraq.

"I mean, they crossed the border into Iraq before we even knew it happened," she said. "This is a group of people who are extraordinarily dangerous, and they'll kill with abandon."