Tehran won't let the death of General Qassem Soleimani go "unpunished," Iranian Foreign Ministry spokesperson Saeed Khatibzadeh said during a press briefing in Tehran on Monday.

"The perpetrators, agents and deputies inside Iraq, as well as outside Iraq, must be brought to justice," Khatibzadeh said. "We will not allow this aggression and this state terrorism to go unpunished."

"We are ready for any scenario, we assess all scenarios, and we are ready to respond to each scenario," Khatibzadeh said. "I hope that [the United States] will stop escalating tensions in these last days before [US President Donald Trump] leaves the White House."

Khatibzadeh called US President Donald Trump's pardon of Blackwater contractors convicted of killing 14 Iraqi citizens in 2007 a "shameful thing" that manifested "one of the dark spots of US presence in Iraq."

Khatibzadeh also called on the US to "return to its obligations" regarding the Iran nuclear deal, before accusing Europe of being "a partner in the violation of the JCPOA."

The Iran nuclear deal, known as the Joint Comprehensive Plan of Action (JCPOA), was signed between Iran and major powers in 2015. Under the agreement, Iran was set to slow down its nuclear programme in exchange for the lifting of economic sanctions.

The US pulled out from the deal in 2018 after an order from President Donald Trump who imposed harsher sanctions on Tehran.