The meeting was "very positive", new Environment Secretary Ranil Jayawardena told GB News' Tom Harwood outside No.10.
The new-look Cabinet met on Wednesday morning to consider a plan to freeze energy bills in order to save households and businesses from financial ruin.
Ms Truss will “strain every sinew” to get the economy growing as she looks to "hit the ground running", her deputy Therese Coffey said.
In her first speech as PM, Ms Truss insisted the nation can “ride out the storm” caused by Russian leader Vladimir Putin’s war in Ukraine.
Liz Truss leading her first Cabinet meeting on Wednesday
Frank Augstein
Members of Liz Truss' Cabinet congregate in Downing Street
Frank Augstein
She conducted a major overhaul to leave few survivors from Boris Johnson’s Cabinet, as she failed to find a role for her leadership rival Mr Sunak.
Allies insisted the changes would “unify” the Tory party, pointing to senior roles for five leadership rivals, Penny Mordaunt, Tom Tugendhat, Suella Braverman, Kemi Badenoch and Nadhim Zahawi.
But Dominic Raab, Grant Shapps, George Eustice and Steve Barclay were among the Sunak supporters dispatched to the backbenches.
Along with Kwasi Kwarteng as Chancellor, the appointment of Ms Braverman as Home Secretary and James Cleverly as Foreign Secretary mean that for the first time in history none of the great offices of state are held by white men.
Jacob Rees-Mogg was appointed as Secretary of State for Business, Energy and Industrial Strategy.
As well as appointing her Cabinet, on her first night in No 10 Ms Truss made her first call to a fellow foreign leader, to President Volodymyr Zelenskyy, accepting an invitation to visit his nation soon.
She went on to speak to Joe Biden, with the White House’s account of the call making clear the US President stressed the need to come to an agreement with the EU over post-Brexit legislation on Northern Ireland.
The transatlantic relationship could be strained if Ms Truss pushes ahead with the plan to override parts of the Northern Ireland Protocol, with Mr Biden proud of his Irish roots and taking a keen interest in the issue.