The shadow treasurer named cuts to foreign aid spending and mocking concerns on climate change as factors in the Solomon Islands' recent signing of a security pact with China.
Mr Chalmers wants to boost foreign aid spending but says that isn't "the whole story".
"We need to rebuild our diplomatic capacity," Mr Chalmers told ABC's Insiders on Sunday.
"Foreign aid will be part of it, being a credible partner on climate is part of it."
Mr Chalmers also outlined Labor's safeguard mechanisms for curbing climate emissions, with businesses to be given two choices: cut emissions or purchase carbon credits, with current abatements costing $24 per tonne.
Labor hasn't ruled out the opening of new coal mines, and Mr Chalmers said future projects would get the green light if they stacked up environmentally and financially.
He said Labor's emissions modelling, aiming for a 43 per cent cut in emissions by 2030, takes into account new coal mines.
"We have said repeatedly that there is a future for coal for the time being because there is an appetite for coal around the world," Mr Chalmers said.
Deputy Prime Minister Barnaby Joyce shot down Labor's promises to help the energy industry transition out of coal, saying there were no alternative jobs in some regions.
"We're not going to be saying to people the word 'transition' because that equals to unemployment," Mr Joyce told Insiders.
But Mr Joyce backtracked on an amendment he moved in parliament advocating the government underwrite new coal mines.
He also said the government wouldn't underwrite hydrogen energy projects, despite it being a big part of the coalition's plans to curb emissions.
The Morrison government hopes, but has not set a target, to cut emissions by about 26 per cent by 2030 and both major parties have pledged net zero by 2050 targets.
Both the coalition's and Labor's 2030 targets have been criticised by experts for falling well short of what's needed for meaningful action on climate.
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