UNITED NATIONS -- UN Secretary-General Antonio Guterres is deeply alarmed by Iran's missile attack on a US military base in Qatar, said his spokesman on Monday.

The secretary-general is deeply alarmed by the further escalation of the conflict in the Middle East. From the outset of the crisis, the secretary-general has repeatedly condemned any military escalation, including Monday's attack by Iran on the territory of Qatar, said Stephane Dujarric, the spokesman, in a statement.

Guterres reiterates his call on all parties to stop fighting. He also urges all UN member states to uphold their obligations under the UN Charter and other rules of international law, said the statement.