CNN) -- U.S. Secretary of State Condoleezza Rice -- responding to Iran's latest test-firings of missiles -- has made it clear Thursday her country is determined to prevent Tehran from threatening the interests of itself and allies like Israel.

Rice was speaking at a news conference in the Georgian capital of Tblisi after Iran test-fired a long-range missile. According to Iranian state media, Iran conducted more test-firings Thursday.

Rice said the United States has been working with allies to "make certain that they are capable of defending themselves" against any threat from Iran.

"We take very strongly our obligation to help our allies defend themselves and no one should be confused about that," she said.