A top US lawmaker said Wednesday she had introduced legislation to safeguard a US-Australia nuclear cooperation deal potentially threatened by a ticking US legislative clock.

Republican Representative Ileana Ros-Lehtinen, likely to chair the House Foreign Affairs Committee when a new US Congress convenes in January, said however that a similar accord with Russia should be allowed to lapse.

"In Australia, we have a proven ally. Serious questions remain about the Russian Federation as a responsible US partner," she said in a statement.

Under US law, nuclear cooperation accords cannot go into effect before the end of a congressional review period set at 90 days of continuous session -- a threshold that the current Congress may not reach, depending on the length of a year-end "lame duck" session.

Ros-Lehtinen said her bill would ensure that the US-Australia accord "will not be interrupted by a technicality," allowing "nuclear commerce with this key ally to continue without interruption."

US President Barack Obama submitted the accord to the Congress for approval on May 5, promising it "will advance the nonproliferation and other foreign policy interests of the United States."

Ros-Lehtinen said a nuclear cooperation deal with Russia "should be stopped" because Moscow "continues to undermine US interests in Iran, Venezuela, Central Asia, and elsewhere."

"Russia promotes nuclear proliferation through its reckless policies of selling nuclear facilities, technology, and materials to any country with ready cash, including constructing the Iranian nuclear reactor at Bushehr," she said.

"If the legislative clock stops before the Russia agreement is approved, the president should not resubmit it to Congress until Moscow has changed course and has lived up to the example set by Australia," said Ros-Lehtinen.