Deputy Prime Minister and Foreign Minister Tanasak Patimapragorn insists that Thailand remains neutral when it comes to foreign affairs.
His comments come after critics suggested the country is leaning towards Russia and China.
Tanasak: 'We play straight with all sides' (Bangkok Post photo)
Thailand maintains its usual foreign policy and has never chosen sides, said Gen Tanasak.
Russia has been a friend of Thailand for 118 years, he said.
The US and Thailand have maintained close relations for over 180 years.
It's the nature of Thai people to be hospitable and welcome visitors, said Gen Tanasak.
Thailand has purchased weapons from Russia in the past, not only after the visit to Thailand by Russian Prime Minister Dmitry Medvedev last week, he said.
Actually, Thailand buys weapons from the US, China and Russia, he said, adding the current deals Thailand has with Russia were initiated by the previous government and the current government only chose to continue with them.
Aside from military hardware, the two countries also discussed how to restart the trade of consumer products and agricultural trade that the previous Thai government had chosen to ignore, he said.
"We're open and always play it straight with any sides. We've never befriended anyone because we want to make others jealous. I can insist this government is honest and frank. We are willing to cooperate with every country in the international community. And of course we play by the rules," Gen Tanasak said.
The visit of the Russian prime minister on Tuesday and Wednesday, the first of its kind in 25 years, resulted in joint agreements in a number of areas, from energy to military hardware.
These agreements prompted critics to suggest Thailand's foreign policy was shifting at a time when the US was putting pressure on the government over the May 22 coup and its impact on the Thai political situation. The US wants Thailand to return to a democracy.
The government is also talking to China about arms deals. Deputy Prime Minister and Defence Minister Gen Prawit Wongsuwon led the armed forces' leaders on a three-day visit to China last week to discuss purchasing military hardware such as submarines.
"It's not surprising Thailand has opted to purchase more weapons from Russia especially after the US cut down on so-called 'military assistance' to Thailand,'' said former senator Paisal Puechmongkol, writing on his Facebook.
When Thailand purchased a large volume of weapons from the US, that country called the purchases "military assistance'' and the deals normally came with many conditions, said Mr Paisal.
If Thailand chooses to buy weapons primarily from Russia and China, Asia will become the number one customer of those two countries, he said. The US would lose out as demand for its dollars would decline.