In a mid-November press conference last year, Ardern told reporters that Cabinet hadn't yet made the final decision as to who it would be supporting for the nomination of the OECD's Secretary-General.
"[There are a] number of things that we want to take into account, and what I would say is that we have a wide range of considerations; citizenship is not the only one."
And in December, she told her post-Cabinet press conference that Cabinet "had discussed the appointment" but had yet to announce it.
But she did say that she would "do that shortly ... I'll make sure that we do that before the end of the year".
Liddell's candidacy for the Secretary-General role came into stark focus after the US Capitol riots, which claimed the lives of five people.
US lawmakers in Congress have voted to impeach Trump for his role in inciting the violence – the Senate has not yet voted.
A number of key Trump officials and members of his cabinet resigned in the wake of the riots. Liddell, however, said he was staying on Trump's staff until he leaves office.
Although she won't say if she's supporting Liddell's bid, Ardern did condemn the storming of the Capitol Building, saying it was "wrong".
"Democracy - the right of people to exercise a vote, have their voice heard and then have that decision upheld peacefully should never be undone by a mob. Our thoughts are with everyone who is as devastated as we are by the events of today. I have no doubt democracy will prevail," she said in a Tweet at the time.
National had previously supported Liddell's selection, but leader Judith Collins last week said the party had changed its mind after the US Capitol riots.
"The rioting that took place in the US Capitol was a disgraceful attack on democracy that has rightly tarnished those who incited and enabled the violence," Collins said.
"Mr Liddell's ties to the Trump Administration cannot be overlooked here, making it difficult to see how he would be suitable to uphold the OECD's strong commitment to democracy."
Not long before Collins' statement, the Act Party was singing a similar tune.
"Following Mr Liddell's failure to denounce recent events, Act can no longer support him in his candidacy," the party's deputy leader Brooke van Velden told Newshub.
Liddell – who has been described as Trump's right-hand man – finishes up in the White House in a few days.
After the riots, a number of senior Trump staff resigned but Liddell said he would stay on until the end as it was the right thing for the country.
He told the Herald he was "horrified, like everyone else," by Capitol riots last week.
