Russia warns US over Start nuclear treaty changes
21 December 2010 Last updated at 09:47 GMT
Russia has warned US lawmakers that any changes to the new nuclear arms disarmament treaty could destroy the pact.
Foreign Minister Sergei Lavrov said the New Start treaty "cannot be reopened, becoming the subject of new negotiations" according to remarks reported by Interfax news agency.
Two-thirds of the 100 US senators must back the treaty for it to be ratified.
Matt Frei reports.