U.S. Secretary of State Mike Pompeo on Friday carried out a flurry of telephone diplomacy, speaking with foreign leaders following Washington's killing of a top Iranian commander that has sent the region on edge.

Pompeo spoke with China's chief diplomat Yang Jiechi, British Foreign Secretary Dominic Raab, French Foreign Minister Jean-Yves Le Drian, German Foreign Minister Heiko Maas, Pakistani Chief of Staff General Qamar Javed Bajwa and Afghan President Ashraf Ghani, according to the State Department.

The flurry of diplomatic activity comes as the region braces for possible retribution from Iran after the U.S. confirmed it carried out a strike near Baghdad's airport that killed Qasem Soleimani, commander of the elite Quds Force division of Iran's Islamic Revolutionary Guards Corps.

Soleimani's slaying marks a dramatic escalation in tensions between the U.S. and Iran, which have often been at a fever pitch since President Donald Trump chose in 2018 to unilaterally withdraw the U.S. from the nuclear pact world powers struck with Tehran.

Iranian Supreme Leader Ali Khamenei, who gave Soleimani the country’s highest honor last year, vowed “severe retaliation” in retaliation for his killing as Trump struck a hawkish tone of defiance.

Following the death of an American contractor in rocket attacks on a U.S. base in Iraq on Friday, Washington carried out a series of strikes in Iraq and Syria on Sunday that led to the deaths of at least 25 fighters from the Iran-backed Kataib Hezbollah militia group.

The strikes were the first major attack by the U.S. on an Iran-linked group since the withdrawal of troops from Iraq in 2011.

The U.S. embassy in Baghdad was then attacked by a large crowd of angry protesters on Tuesday, leading to a two-day standoff between U.S. forces and protesters.

The Pentagon accused Soleimani of plotting the embassy attack and planning to carry out additional attacks on U.S. diplomats and service members in Iraq and the region.

Trump said Soleimani was behind the deaths and woundings of thousands of Americans, and claimed "he was directly and indirectly responsible for the death of millions of people, including the recent large number of PROTESTERS killed in Iran itself."

Although Iran is "not able to properly" admit it, Soleimani was both "hated and feared" within the country, the U.S. president said in a series of tweets.

"He should have been taken out many years ago!" Trump added.