Iran and Turkmenistan on Saturday announced a series of trade deals and said they were determined to boost bilateral ties, ISNA news agency reported, according to dpa. Turkmen President Gurbanguly Berdymuhammedov and Iranian President Mahmoud Ahmadinejad said the two states would expand cooperation in the fields of oil, gas and transportation, at the end of the two-day summit in Tehran. The two neighbouring countries agreed to the export of 30 Iranian busses in the short-term and 310 busses within the next four months to Turkmenistan. The two presidents also agreed to establish a bridge enabling trade to third countries via each other's countries. Ahmadinejad also said he accepted an invitation by Berdymuhammedov to visit Ashgabat in the near future. Tehran and Ashgabat established diplomatic relations shortly after Turkmenistan's independence from the Soviet Union in 1991 and since then, the two countries have maintained good political and trade relations. Symbolic of the relations between two neighbouring countries is a dam along the joint border dubbed a "dam of friendship" which secures both sides some 650 to 950 million cubic metres of water per year and boosts agricultural irrigation.