Senator John McCain said the United States has been backing away from a brewing fight with Iran, while that country moves ever closer to having nuclear weapons.
McCain opened a Senate hearing Wednesday by saying that Iran will get the bomb unless the United States acts more boldly.
Speaking figuratively, the Arizona Republican said the U.S. keeps pointing a loaded gun at Iran but failing to "pull the trigger."
During the hearing, a top diplomat said the United States is working as fast as it can to win new international sanctions on Iran.
The State Department's No. 3 official predicted that a resolution will emerge from the United Nations Security Council this spring. And Under Secretary of State for Political Affairs William Burns called the case for new penalties urgent, saying he expected China will agree to some form of sanctions.
"I think we and the Chinese agree that we need to send a strong message to Iran," Burns said.
But Burns said it would be "very difficult" to get either China or Russia to agree to sanctions that would cut off the flow of refined petroleum products to Iran, a proposal backed by many U.S. lawmakers.
Iran could produce enough highly enriched uranium needed for a single nuclear bomb in as little as one year but would probably need three to five years to build a "usable" atomic weapon, top Pentagon officials said Wednesday.
Gen. James Cartwright said that, historically, it takes a country three to five years to make such a leap. Cartwright is the nation's second highest-ranking military officer.
The timeline he cited Wednesday could be shortened if Iran pursued ways to deliver a weapon at the same time as it worked to build a bomb.
Western powers fear Iran wants to develop nuclear weapons under the cover of a civilian atomic program. Tehran says its program is intended only for peaceful power generation.
Second round of talks
At the United Nations, six major powers held a second round of talks on possible new sanctions against Iran for refusing to negotiate on its nuclear program.
The United States and its Western allies are pressing for quick adoption of an array of tough sanctions, but Russia and China are still hoping that diplomacy will lead Iran to the negotiating table and have indicated they will only agree to much weaker measures if Tehran refuses.
After more than three hours of talks, Russia’s U.N. ambassador, Vitaly Churkin, and China’s U.N. ambassador, Li Baodong, both called the discussion “very constructive” and Churkin said the six would meet again “very soon.”
“We have a very important consultation with a focus on diplomacy,” Li said earlier, while heading into the talks at the U.S. Mission.
On the table at the closed-door meeting is a draft U.N. resolution circulated by the U.S. in January, with some changes proposed by Britain, France and Germany. Ambassadors from the six countries held their first closed meeting on the draft last Thursday.
The draft resolution focuses on five areas: strengthening the existing arms embargo, targeting Iran’s powerful Revolutionary Guards, imposing new sanctions on its energy sector, and strengthening sanctions on its shipping and finance sectors, a U.N. diplomat familiar with the talks said. It would also add new names of individuals and entities to a list of those subject to an asset freeze and travel ban for their proliferation-related activities.
The Associated Press and Reuters contributed to this report.