Nick Thomas-Symonds struggled to respond to backlash over the changes to inheritance tax for farmers.
The home secretary would not say whether the Israeli PM would be taken into custody if he comes to the UK.
Kennedy has since apologized for the remarks, but with a staunchly pro-Trump twist.
Lib Dem deputy leader Daisy Cooper said allies have been to slow to act over the war.
The landmark legislation comes before the Commons on November 29.
The former Florida attorney general is a longtime ally of the president-elect after first endorsing him in 2016.
Republicans seem relieved they won't have to vote on whether Gaetz should be attorney general.