Uzbek First Deputy Prime Minister Rusatm Azimov in December told his Tajik counterparts that unspecified issues from Russian and Chinese buyers meant signing a natural gas deal wasn't possible.
Davlat Nazriev, a spokesman for the Tajik foreign minister, said the Uzbeks cut gas supplies to its energy company as a result.
"TajikTransGaz applied to Uztransgaz to sign an agreement on supplying natural gas in 2012 but the Uzbek party postponed the signing of the contract," he was quoted by Russia's state-run news agency RIA Novosti as saying.
The Uzbek company, Uztransgaz, in November raised the price of natural gas for Tajikistan. Deliveries to Tajikistan last year were around 700 million cubic feet short of the 6.3 billion cf outlined in the 2011 agreement.
Authorities at the Tajik railroad commission said the government is upset with tariff increases imposed by Uzbekistan for rail freight bound for the country, reports Radio Free Europe/Radio Liberty. The tariff for 1 ton of wheat flour was raised from $74 in 2011 to more than $88 as of the first of the year.