Russia says the United States is justifying terrorism against the Syrian government by failing to condemn atrocities committed by the armed groups fighting against Damascus.

Russian Foreign Minister Sergei Lavrov on Wednesday criticized Washington for supporting armed groups in Syria and its failure to condemn the July 18 terrorist bomb attack in the Syrian capital that killed at least four high-profile security officials, including Defense Minister Dawoud Rajiha and his deputy Assef Shawkat who is also President Assad's brother-in-law.

“This is direct endorsement of terrorism. How are we supposed to understand that?” Lavrov told reporters in Moscow, Russia Today reported.

“This is a sinister position, I cannot find words to express our attitude towards that,” he added.

“This is direct endorsement of terrorism. How are we supposed to understand that?” Sergey Lavrov shared his astonishment at a press conference in Moscow.

The top Russian diplomat also criticized the U.S. ambassador to the United Nations Susan Rice for arguing last week that the violence in Damascus meant the UN Security Council had to agree on a sanctions resolution against the Syrian government.

"In other words, to say it in plain Russian, this means 'we (the United States) will continue to support such terrorist acts for as long as the UN Security Council has not done what we want'," Lavrov said.

He also criticized a recent Arab League call for Assad's rapid resignation in return for a safe exit, accusing the bloc of offering 'conflicting solutions' to the Syrian issue.

Russia, along with China, has so far vetoed three Security Council resolutions against Syria and has repeatedly expressed opposition to outside meddling in the country's internal affairs.

Russia slams anti-Syria EU bans

Meanwhile, Russia has also condemned the new round of European Union (EU) sanctions imposed against Syria, describing the move as a “blockade” against Damascus.

“Essentially, the measures taken by the European Union can be considered a declaration of a sea and air blockade of Syria,” the Russian Foreign Ministry said in a statement on Wednesday.

The statement once again put emphasis on Moscow’s opposition to the Western-led unilateral sanctions and added that “Russia does not recognize them and believes them to be counter-productive.”

It also said that the EU legislation must be investigated to determine whether it is in line with international law.

According to the statement the new round of embargoes on Syria violated the UN-Arab League envoy Kofi Annan’s peace plan.

Syria has been experiencing unrest since March 2011, with demonstrations being held both against and in support of President Assad's government.

The Syrian government says outlaws, saboteurs, and armed terrorists are the driving factor behind the unrest and deadly violence while the opposition accuses the security forces of being behind the killings.

Damascus also says that the chaos is being orchestrated from outside the country and the security forces have been given clear instructions not to harm civilians.

(Source: agencies)