Russia admits military presence on Syrian soil
Russia's foreign ministry spokeswoman has accused the West of creating "strange hysteria" over Russian activities in Syria, saying that Moscow has been openly supplying weapons and sending military specialists to Syria for a long time.
The US has expressed concern about signs of a Russian military build-up in Syria.
On Wednesday, Reuters reported that two tank landing ships and warplanes had been sent to Syria sometime over the past few days.
Two US officials alleged that there were also signs that Moscow has deployed a small number of troops in Syria. So far, Russia's intentions remain unclear the unnamed officials said.
The US believes that this might be an attempt to bolster Russia's long-term Arab ally with air support, against the Islamic State group but also against rebel forces, which are supported by Washington.
Foreign Ministry spokeswoman Maria Zhakarova told journalists Wednesday that "Russia has never made a secret of its military-technical cooperation with Syria."
She added that she could "confirm and repeat once again that Russian military specialists are in Syria to help them master the weapons being supplied".
President Vladimir Putin and other Russian officials also have confirmed in recent days that Russia has military experts in Syria to train its military on how to use Russian-supplied weapons.
The diplomatic dispute over Russian intervention in Syria's war heated up after disagreements with European countries about the use of their airspace for supply flights to the war-torn country.
Moscow has already lashed out at Black Sea neighbour Bulgaria after it refused to allow Russian cargo planes bound for Syria to fly over its territory.
Reports from Syria suggest that Russia is building a massive airbase in Latakia province.
There have also been signs that Russian troops are taking part in the conflict on the ground, backing Damascus with advisers and troops.
Russian Deputy Foreign Minister Mikhail Bogdanov alleged that Bulgaria and Greece are facing pressure from Washington.
Bulgaria said that it would allow Russian aircraft to use its airspace, so long as the cargo could be inspected.
"If our Russian colleagues agree for their flights to be inspected at a Bulgarian airport, we will grant them a permit," Bulgarian Foreign Minister Daniel Mitov told journalists.
Earlier, Bulgaria's foreign ministry said it was refusing to allow Russian military transport aircraft to fly through its airspace en route to Syria from 1 to 24 September.
It said without elaboration that the reason for the refusal was "incorrect information" about the purpose of the flights and the cargo.
Greece on Wednesday denied it had angered Moscow by examining a US request to ban Russian supply flights to Syria.
"No displeasure or any other negative comment has been expressed from anyone," foreign ministry spokesman Constantinos Koutras said in a statement.
Moscow on Tuesday said it had demanded answers from NATO members Greece and Bulgaria after Sofia banned Russian supply flights to Syria from its airspace and Athens said it had been asked by Washington to do the same.
"If anyone - in this case our Greek and Bulgarian partners -- has any doubts, then they, of course, should explain what the problem is," deputy Russian foreign minister Mikhail Bogdanov told the Interfax news agency.
"If we are talking about them taking some sort of restrictive or prohibitive measures at the Americans' request, then this raises questions about their sovereign right to take decisions," he said.
Giving an entirely different take, the Greek foreign ministry spokesman insisted on Wednesday that "Greece's handling of the issue had been greatly appreciated."
Washington has expressed concern following reports suggesting Moscow may be boosting military support to Syrian President Bashar al-Assad.
Greece said it had received a request from Washington to prevent two state civil aviation Russian planes flying through its airspace between 1 and 24 September.
Speaking to AFP on Tuesday, a Greek government spokesperson said Russia had first requested use of its airspace "25 days ago" but had later decided to use an alternative route.
Asked if Athens would refuse permission for Russian overflights in future, the spokesperson said the situation was "delicate" but that Russia would likely avoid using the route.
Vladimir Djabarov, vice-president of the Russian foreign affairs council on Tuesday told state press agency TASS that Russia was only supplying "humanitarian cargo" to Syria, saying it was "not profitable to transport weapons by plane".
Djabarov also dismissed the importance of using Greek airspace, saying that the majority of flights to Syria went via the Caucasus and Iran.