Russian President Vladimir Putin’s attempts to deepen ties with Iran amid the Ukraine conflict represents a “profound threat,” US National Security Adviser Jake Sullivan said on Wednesday, Reuters reported.

The day before, Sullivan said that Iran was allegedly preparing to supply Russia with several hundred drones. The Iranian Foreign Ministry denied the information.

Putin plans to visit Tehran next week, where he will meet with the presidents of Iran and Turkey.

Sullivan called the timing of Putin's trip "interesting." “Russia deepening an alliance with Iran to kill Ukrainians is something that the whole world should look at and see as a profound threat,” Sullivan said.