The top U.S. diplomat also voiced skepticism about Iran's new claims that it had made major progress in its nuclear program and tested more advanced equipment for enriching uranium.
"We do not attribute any particular meaning, with respect to the range of issues that we are looking to address with the Iranians, from this particular statement," Clinton said at a news conference when asked about an Iranian statement that it was now running 7,000 enrichment centrifuges.
Enriching uranium can produce fuel for a nuclear power plant or, if purified to a much higher degree, provide material for an atomic bomb.
"We don't know what to believe about the Iranian program. We've heard many different assessments and claims over a number of years," said Clinton of Iran's latest claims.
Clinton reiterated that Iran must abide by international obligations over its nuclear program, which the West suspects is cover for building an atomic bomb and Tehran argues is for peaceful purposes to generate electricity.
"It would benefit the Iranians in our view if they cooperated with the international community, if they abided by a set of obligations and expectations that affect them and by which we believe they are bound. We are going to continue to insist on that," said Clinton.
President Mahmoud Ahmadinejad inaugurated Iran's first nuclear fuel production plant on Thursday, but also said Tehran was ready for talks with the West if those discussions were based on "justice and respect."
The six major powers dealing with Iran, including the United States, met in London this week and invited Tehran to a new round of talks about its nuclear program.
In a dramatic reversal of the former Bush administration's policy of isolating Tehran, Washington said it would now have a permanent seat at any future negotiations with Iran about its nuclear program.
WAITING FOR A RESPONSE
Asked about Ahmadinejad's comments on speaking to the West, State Department spokesman Robert Wood said the United States was still waiting for a response from Iran.
"There are a lot of issues between us and we would like to move forward substantively and positively on them. It will be up to Iran whether it wants to engage with us," he added.
Wood urged Iran to take up the West's offer last year of financial and diplomatic incentives in exchange for giving up sensitive nuclear work.
He also repeated an appeal for Iran to free imprisoned U.S. journalist Roxana Saberi and said espionage charges announced by Iran against her were "baseless and without foundation."
"We would like to see her released as a humanitarian gesture," said Wood, who also questioned the transparency of Iran's legal process.
The human rights group Freedom House also demanded Saberi's immediate release and said her case was the latest in a string of attacks on press freedom in Iran.
"The Roxana Saberi case is the latest instance of an alarming trend in which Iran is imprisoning journalists and bloggers and charging them with serious crimes," said Jennifer Windsor, Freedom House executive director.
