United Nations Secretary-General Antonio Guterres believes that attacks in Beirut and Tehran this week mark a "dangerous escalation" of the conflict in the Middle East, his spokesperson said on Wednesday.

"It is increasingly clear ... that restraint alone is insufficient at this extremely sensitive time. The Secretary-General urges all to vigorously work toward regional de-escalation in the interest of long-term peace and stability for all," spokesperson Stephane Dujarric said in a statement.