ASHGABAT, Oct 13 - Turkmen President Saparmurat Niyazov on Thursday postponed indefinitely signing a 25-year natural gas agreement with Ukraine, saying the deal must also be approved by Russia.

Ukraine and Turkmenistan have been discussing signing of the agreement over the past two years, but Ashgabat had been repeatedly postponing the deal. Niyazov was supposed to visit Ukraine in November to sign the deal.