Although the Syrian government has reclaimed the embattled city of Aleppo, civil war within the nation is far from over. On Christmas Eve, Russian airstrikes against several towns in rebel-held areas of the country were said to have injured and killed civilians, as reported by the U.S.-backed opposition group forced out of the city two days prior. Now, Russia has accused the United States of committing a “hostile act” by easing restrictions on arming the Syrian rebels.

Departing President Barack Obama signed the annual defense policy bill into law last week, which included language permitting the United States to send surface-to-air missiles to rebel groups in Syria. Russian foreign ministry spokeswoman Maria Zakharova called the policy change a hostile act, and suggested that the weapons would soon end up “in the hands of jihadists with whom the sham ‘moderate’ opposition have long acted jointly.”

“Such a decision is a direct threat to the Russian air force, to other Russian military personnel, and to our embassy in Syria, which has come under fire more than once. We therefore view the step as a hostile one,” Zakharova said in a statement from Moscow.

President Obama and other U.S. officials have been extremely critical of Russian airstrikes in support of Syrian President Bashar al-Assad’s regime. The Obama administration recently expanded the list of Russians subjected to sanctions as a result of Russia’s military annexation of Crimea in 2014, and American Ambassador to the U.N. Samantha Power recently asked Russia and its allies in Syria if they were “incapable of shame” regarding their actions in Aleppo. Russia and Iran both assisted the Syrian regime in retaking portions of the city that had been held by rebels.

In a separate statement, Zakharova addressed the increased sanctions imposed by the Obama administration by suggesting that Russia would respond in due time. “It is high time for Washington to understand that these attempts are futile and doomed to fail, and that the new restrictions, naturally, will not go unanswered. We will decide the specific type, time, and scope of our response.”

Russia doubled down on their idea that weapons provided to Syrian rebels would quickly fall into the hands of terrorists and jihadis, going so far as to suggest that the U.S.-backed rebels aren’t any different from the pockets of ISIS fighters both U.S. and Russian forces have taken military action against in Syria over the past year.

“Washington has placed its bets on supplying military aid to anti-government forces who don’t differ than much from bloodthirsty head-choppers. Now, the possibility of supplying them with weapons, including mobile anti-aircraft complexes, has been written into this new bill,” Zakharova said in her statement.

As President Obama’s time in office comes to an end, some Russians have accused him of trying to ensure tensions remain high between the two nations. Trump called for normalized relations between Russia and the United States throughout his campaign, and American intelligence agencies have announced with some level of certainty that Russian hackers attempted to discredit Democrat candidate Hillary Clinton in her campaign against Trump. This level of friendly discourse could be attributed to Russia’s desire to have sanctions against it eased, but many in both parties have grown uneasy with the president-elect’s seemingly friendly demeanor toward Russian President Vladimir Putin.