The West’s effort to potentially send modern fighter jets to Ukraine “carries enormous risks,” Russia’s Deputy Foreign Minister Alexander Grushko warned on Saturday, according to Russian state news agency TASS.

The minister’s comments in an interview with TASS come in the wake of the U.S. getting behind a joint international effort to train Ukrainian pilots to use modern fighter aircraft including F-16s. This could also pave the way to eventually send advanced Western combat jets to Ukraine, according to a senior administration official. 

Ukrainian President Volodymyr Zelenskyy welcomed the U.S. decision in a tweet on Friday, saying that it “will greatly enhance our army in the sky.” He added that he counted on discussing “the practical implementation of this decision” at the G7 summit in Hiroshima, Japan. 

“We can see that Western countries continue to stick to an escalation scenario, which carries enormous risks for them,” Grushko said in the interview. “In any case, we will take it into account when making plans. We have all the necessary means to achieve our goals,” he added. 

The decision from the U.S. follows a concerted effort by Ukraine to get its allies to supply its military with modern jets, in particular the U.S.-built F-16s.