by Xinhua writer Zhi Linfei

CAIRO, Jan. 4 (Xinhua) -- The United States dramatically escalated tensions in the Middle East by killing a senior Iranian commander in Iraq on Friday, which threatens to open a Pandora's box of renewed conflict in this volatile part of the world.

Qassem Soleimani, commander of Quds Force of Iranian Islamic Revolution Guards Corps, was killed in a U.S. airstrike on Baghdad International Airport. This came after Iraqi protesters stormed the U.S. embassy compound in Baghdad on Tuesday to protest against earlier U.S. air raids on Kata'ib Hezbollah, a pro-Iran militia, which killed dozens of its fighters.

U.S. President Donald Trump, who ordered the killing, defended it as a move to thwart imminent attacks on U.S. targets planned by Soleimani.

Many countries, including Iraq, denounced the U.S. act as a blatant violation of Iraq's sovereignty, while Iran strongly condemned it as an "act of terrorism" committed in clear violation of international law.

Russian Foreign Minister Sergei Lavrov warned that the U.S. move is fraught with grave consequences for regional peace and stability.

Contrary to the U.S. claim that killing Soleimani was aimed at preventing a war in the region, the move has increased the risk of war by aggravating the already red-hot tensions created after Washington's exit from the 2015 Iranian nuclear pact and its exerting "maximum pressure" on Tehran.

Iran's supreme leader Ayatollah Ali Khamenei on Friday vowed "severe revenge" on the United States over Soleimani's assassination. Many fear that Iran could be provoked to take retaliatory actions against the United States and its allies in the region where any armed conflict could rapidly spiral out of control.

The international community has urged the utmost restraint by all relevant sides to pursue de-escalation in the Gulf area.

UN Secretary-General Antonio Guterres on Friday called for exercising "maximum restraint" by all related parties, citing that the world cannot afford "another war in the Gulf."

The Chinese Foreign Ministry on Friday urged relevant parties, especially the United States, to remain calm and restrained to avoid further escalating tensions in the region.

Canadian Foreign Minister Francois-Philippe Champagne on Friday called on all sides to exercise restraint and pursue de-escalation.

History in the region has shown that responding to violence with violence would only beget more violence. It is now imperative for all concerned parties to refrain from taking further provocative actions, and immediately cool the situation through diplomacy and other peaceful means.