Informed sources said on Sunday Switzerland recently approached the Iranian Oil Ministry officials for the start of negotiations over importing gas, Fars News Agency reported.
Greece has indirectly called for Iran's gas exports since the European country's officials believe Iran can transfer gas via Turkey and then to other countries across Europe.
Other countries, which have entered into direct gas talks with Iran, include Germany (a member of the world powers negotiating with Tehran over its nuclear program), Poland, Japan, Austria, Oman, Turkey and Iraq.
According to the sources, the European and other countries' officials and analysts believe Iran is the safest energy supplier in the world, especially after the Russia-Ukraine crisis threatens to stop Russian gas supplies to Europe.
The Iranian energy sector is facing unilateral US sanctions that punish any third party working with Iran.
They have dismissed US sanctions as inefficient, saying that they have numerous partners for trade and exports.
Some European countries have recently voiced interest in making investments in Iran's energy sector after a gas deal was signed between Iran and Switzerland, regardless of US sanctions.
The National Iranian Gas Export Company and Switzerland's Elektrizitaetsgesellschaft Laufenburg signed a 25-year deal in March 2010 for the annual delivery of 5.5 billion cubic meters of gas.
In mid-February, media reports said Ankara started talks with Iran for the construction of Iran-Turkey-Europe Natural Gas Pipeline Project (ITE) to deliver gas to Europe via Turkey.
The pipeline project is being considered by Turkey as international sanctions against Iran's energy sector are declining following the implementation of Iran's nuclear deal with the world powers.
For transit of natural gas sourced in Iran through Turkey, the Iranian Oil Ministry and Turkey's Energy and Natural Sources Ministry signed an "Agreement Protocol" on November 17, 2008.
The protocol also provides for Turkey to be able to procure its natural gas requirement from the pipeline under the project, if required.
The total length of the pipeline under the project is about 5,000 km. The length of the pipeline within the eastern and western borders of Turkey is about 1,750 km. The annual gas target for Europe under this project is 35 billion cubic meters.
Turkey's part of the ITE Natural Gas Pipeline Project will be from the Turkey- Iran border to the Ipsala/Edirne Greece border, passing through Agri, Erzurum, Erzincan, Gumushane, Sivas, Yozgat, Kirsehir, Kirikkale, Ankara, Eskisehir, Bilecik, Kutahya, Bursa, Balikesir, Canakkale and Tekirdag.
Iran owns the world's largest natural gas reserves after Russia and is also Turkey's second biggest gas supplier after Russia.