By Jonathan Landay and Aleksandar Vasovic
WASHINGTON/BELGRADE (Reuters) - Serbia has agreed to supply arms to Kyiv or has sent them already, according to a classified Pentagon document, despite the country's professed neutrality in the Ukraine war and refusal to sanction Russia over its 2022 invasion.
The document, a summary of European governments' responses to Ukraine's requests for military training and "lethal aid" or weapons, was among dozens of classified documents posted online in recent weeks in what could be the most serious leak of U.S. secrets in years.
The document is marked Secret and NOFORN, prohibiting its distribution to foreign intelligence services and militaries. It is dated March 2, and embossed with the seal of the office of the Joint Chiefs of Staff.
Reuters could not independently verify the document's authenticity.
Serbia's Defense Minister Milos Vucevic dismissed the document's assertions as "untrue" in a statement on Wednesday.
"Serbia did not, nor will it be selling weapons to the Ukrainian nor the Russian side, nor to countries surrounding that conflict," Vucevic said.
Entitled "Europe|Response to Ongoing Russia-Ukraine Conflict," the Pentagon document in chart form lists the "assessed positions" of 38 European governments in response to Ukraine's requests for military assistance.
The chart showed that Serbia declined to provide training to Ukrainian forces, but had committed to sending lethal aid or had supplied it already. It also said Serbia had the political will and military ability to provide weapons to Ukraine in the future.
In his statement, Vucevic said there was a possibility that Serbia-made weaponry and ordnance could "magically appear" in the conflict, but "that has absolutely nothing to do with Serbia."
"Someone clearly wants to drag Serbia into that conflict, but we are diligently maintaining our policies," he added.
President Aleksandar Vucic's office did not respond to a Reuters request for comment but the Serbian foreign ministry issued a statement denying that the country is supplying military equipment to Ukraine.
The Pentagon did not immediately respond to Reuters questions about the document's reference to Serbia and has previously declined to comment on the leaked documents.
TIES TO RUSSIA
Vucic's government has professed neutrality in the Ukraine war, despite the country's deep historic, economic and cultural ties with Russia.
"If this document is accurate, it either shows Vucic's duplicity vis a vis Russia or he's under enormous pressure from Washington to deliver weapons to Ukraine," said Janusz Bugajski, an Eastern European expert with the Jamestown Foundation, a foreign policy institute.
The Justice Department is investigating the leak, while the Pentagon is assessing the damage done to U.S. national security.
The Pentagon chart divided the responses to Ukraine's requests for aid into four categories: countries that had committed to provide training and lethal aid; countries that had already provided training, lethal aid or both; countries with the military ability and the political will "to provide future lethal aid."
Austria and Malta were the only two countries marked "No" in all four categories.
Malta's foreign ministry did not immediately reply to a request for comment. Austria has said its neutrality prevents it from military involvement in the conflict and while it supports Ukraine politically it cannot send the country weapons.
The disclosure of the chart comes just over a month after documents posted in a pro-Russia channel on the Telegram global messaging app purportedly showed the shipment by a Serbian arms maker of 122mm Grad ground-to-ground rockets to Kyiv in November.
The documents included a shipment manifest and a Ukrainian government end-user certificate.
Moscow said in March it had asked Belgrade for an official explanation of the alleged deliveries, the state-run TASS news agency quoted Russian Foreign Ministry spokeswoman Maria Zakharova as saying.
Arms manufacturer Krusik Corp. of Valjevo denied providing rockets or other weaponry to Ukraine. Vucic called the allegations "a notorious lie."
"We didn't export any weapons or ammunition to Russia or Ukraine," he said during a March 5 visit to Qatar.
Reuters could not independently confirm the authenticity of the shipment documentation posted on Telegram.
Vucic has long tried to balance close ties with Moscow with Serbia's goal of joining the European Union.
Although Belgrade has repeatedly condemned Russia's invasion of Ukraine in the United Nations and other international forums, Serbia remains one of the only holdouts among European countries in imposing sanctions on Moscow.
Serbia recognizes Ukraine in its entirety, including areas occupied by Russia since 2014, while Kyiv refuses to recognise independence of Kosovo, Serbia’s predominantly Albanian former province.