US Secretary of State Hillary Clinton turned up the heat Sunday on Republicans over a nuclear arms reduction treaty with Russia, saying the pact was "beyond politics" and must be ratified this year.

Republicans are loath to allow President Barack Obama a victory on a top foreign policy initiative and are seeking to stall passage of the new START treaty until mid-term election gains in Congress take effect next year.

"I would hope that this treaty would be treated as others -- whether it was a Democratic or Republican president -- saw their treaties in arms control with the Russians treated," Clinton said on CBS's "Face the Nation" program.

"And that is: this is beyond politics, let's pass it by an overwhelming bipartisan vote."

Clinton painted Republican senators as playing politics with national security and warned that delaying the accord could impinge on America's ability to verify Russia's nuclear arsenal.

"There is no doubt that the START treaty is in the interests of the United States," she said.

"Don't just take it from me or from the president, look at what the Europeans -- people like (German Chancellor) Angela Merkel or the foreign minister of Poland or the president of any of the Baltic countries or so many others are saying.

"They live next door to Russia, they know that this is in their interests, and they also know that because we have no treaty, there is no inspection going on, there is no verification going on."

The arms treaty was signed by Russian President Dmitry Medvedev and President Barack Obama at an elaborate ceremony in Prague in April -- restricts each nation to a maximum of 1,550 deployed warheads, a cut of about 30 percent from a limit set in 2002.

It would also see the return of US inspectors, who have not monitored Russia's arsenal since the agreement's predecessor lapsed in December 2009.

The agreement, a top Obama foreign policy initiative, requires 67 votes to pass the Senate, meaning a minimum of eight Republicans need to back it.

Clinton used the famous "trust but verify" line made by former Republican president Ronald Reagan about his arms control dealings with Russia as she urged the party to back a pact she said was clearly in the national interest.

"We do not have any inspectors verifying what Russia is doing with their nuclear stockpile or anything else that is going on in their sites," she said in a separate interview with Fox New Sunday. "We cannot go much longer without that capacity restored."

Also speaking on Sunday was the US military's top officer, Admiral Mike Mullen, who underlined the urgent need to get the treaty passed.

"Well, certainly, what I think is that there is a sense of urgency with respect to ratifying this treaty that needs to be both recognized. Historically this has been bipartisan," he told ABC News.

"This is a national security issue of great significance. And the sooner we get it done, the better."

Republicans have complained that they need to be sure that the US nuclear arsenal will be modernized and that the treaty will not hamper missile defense efforts. Obama has already offered Republicans a 4.1-billion-dollar concession to modernize US nuclear stocks.

The task of ratifying the accord will be even tougher in January when a new Congress, elected in November 2 polls in which Republicans routed Democrats, takes office.