US President Donald Trump's team had been discussing, with protected communications at Christmas and New Year holidays, the possibility of a rocket attack to kill Iranian General Qasem Soleimani, Bloomberg reports, citing its sources.

According to the agency, the president’s decision to target the powerful head of the Islamic Revolutionary Guard Corps’ Quds Force came together swiftly, following the death of an American contractor in a Dec. 27 rocket attack by an Iranian-backed militia against a U.S. base in Iraq. Soon after the attack, Trump ordered a handful of his most senior aides to begin planning a strike on the Iranian general, according to three people familiar with the matter. They included National Security Advisor Robert O'Brien, Secretary of State Mike Pompeo, who canceled the trip to the CIS, and Vice President Mike Pence.

The Trump administration had recently asked France and other allies to warn Tehran against killing Americans, according to one of the people. For the president, a red line had been crossed.

As his administration planned the strike, Trump engaged in what looked outwardly like his normal vacation activities. He traveled to his golf course near Mar-a-Lago every day since Christmas. 

The agency notes that The White House opted against notifying Congress ahead of the attack out of concern for security, a person familiar with the matter said. The Department of Homeland Security, which is partially responsible for deterring potential Iranian retaliation on U.S. soil, was only notified of the Soleimani strike after the fact. White House communications officials were excluded from the planning.

A Bloomberg source said US troops had not followed Soleimani before the attack, but the airstrike was launched when intelligence said that the Iranian general was probably at Baghdad airport. Two other agency interlocutors argue that the United States was well aware of when Soleimani had arrived in Baghdad from Lebanon or Syria.