In his first appearance since Labor leader Anthony Albanese was forced into a week-long COVID isolation, the up-and-coming figure criticised Prime Minister Scott Morrison for sending a junior minister, Senator Zed Seselja, instead of Foreign Affairs Minister Marise Payne.

"We should have sent the foreign minister, it's a pretty straightforward thing to do," Mr Clare said.

"If you're serious about Australia's national security - and being serious about our national security means making sure that we've got good relationships with countries in the Pacific and talking to people that are thinking of engaging in a security pact with China - then get on a plane.

"That's what failed to happen here. What happened instead, the foreign minister went to a business function and some bloke called Zed got sent there."

Mr Clare said the government had known about the possibility of it happening since August last year, but failed to pick up the phone and engage with the Pacific neighbour.

Coalition ministers this week denied they had known for months about a possible deal, with Senator Payne confirming she had found out when it appeared in media reports last month despite Mr Morrison later saying it also wasn't a "surprise".

But, following on from Labor leader Anthony Albanese's "gone missing" comments attack on Thursday, Mr Clare continued a similar line, focusing Mr Morrison's "pattern of behaviour".

"You can't sit back on the deck chair in the Pacific and just assume that everything's going to be okay," he said.

"On bushfires, he was too slow to act, on vaccines, when we were locked down waiting for a vaccine, he was too slow to act.

"When it came to the floods, when people were on their roofs, having to hire their own helicopters, he was too slow to act."

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Mr Morrison earlier admitted on Friday morning he hadn't spoken with Solomon Islands' leader, Manasseh Sogavare, since news broke the nation would sign a new security pact with China.

Speaking on the Today show, he said Senator Zed Seselja's visit last week was to "convey some very clear messages on my behalf" but it was too late to change.

"[Mr Sogavare had] made his decision for some time," Mr Morrison said.

"There was no opportunity for, I think, for him to change his mind on this."

The Prime Minister also used a report from The Australian this morning to suggest a Labor government would have done little to stop the deal from happening if it were in power.

The report references a book written by deputy Labor leader Richard Marles in August last year, where he argues it "silly" for Pacific Nations to not engage with China because of Australia's requests.

"Australia has no right to expect a set of exclusive relationships with the Pacific nations," he wrote.

"They are perfectly free to engage on whatever terms they choose with China or, for that matter, any other country. Disputing this would be resented, as the recent past has shown."

Mr Morrison said he found it "outrageous" that Labor was criticising his party given the comments made by Mr Marles.

But Mr Morrison also conceded previous administrations had taken a more colonial-style approach and would seek to respect the decisions made by Pacific nations.

"We're not ... a colonial power, running around throwing our weight around, telling people what to do," he said on Friday.

"We've taken a different approach through the Pacific step up, which treats all the Pacific Island leaders with great respect and understanding their needs and issues."