MOSCOW: Russia and the United States could clinch a replacement for the Strategic Arms Reduction Treaty (START-1) in March or April, Russian presidential aide Sergei Prikhodko said Wednesday.

"March or April is a realistic date," Prikhodko told reporters.

Moscow would agree to sign the document with Washington in the Czech capital of Prague, a Kremlin source said on condition of anonymity.

"Experts close to the American side named Prague as a likely venue for signing (the new treaty). Moscow does not reject this choice," Interfax news agency quoted the source as saying.

Russia and the United States on Monday resumed negotiations to replace the 1991 START-1, which expired on December 5. Disagreements remain over verification and control procedures.

An outline of the new treaty, agreed by Russian President Dmitry Medvedev and US counterpart Barack Obama, includes slashing nuclear arsenals to 1,500-1,675 operational warheads and delivery vehicles to 500-1,000.

"Together with colleagues from the US Senate, we will carry out preparatory work for the synchronized ratification of the treaty," the RIA Novosti news agency quoted the lawmaker saying.

The new document must be ratified by lawmakers of both sides before it comes into effect, he said.

Signing the new START treaty is widely seen as a breakthrough for Moscow and Washington to "reset" ties, which in the final days of the Bush administration plunged to a low unprecedented since the Cold War.