On Saturday, Mr Morrison claimed Australia needed "strength and resilience" to get through the past couple of turbulent years, but acknowledged the approach he had during the pandemic would need to change.

Speaking from the Victorian seat of Deakin, held by the Liberals on a 4.8 per cent margin, the prime minister said that voters could expect a more collaborative leader should he defy polls on May 21.

"I will seek to explain my motives and my concerns, and empathise a lot more," he said.

"But I tell you what, at the end of the day, what matters most is I get the job done."

In Melbourne on Saturday, Mr Morrison urged voters to consider the optimism and opportunities that lie ahead now that the country has moved beyond the lockdown stage of the pandemic.

As part of the upbeat sentiment, he announced the expansion of a program designed to get more high school students active again.

The government's Sporting Schools program expansion would see up to 700,000 more students play sport in school, with more than $20 million being spent on the initiative.

The program, currently available for year 7 and 8 students, will be expanded into years 9 and 10.

As well as competing with Labor, the coalition must fend off high-profile independent candidates in heartland Victorian Liberal seats that are pressuring some of Mr Morrison's top colleagues, such as Treasurer Josh Frydenberg.

The prime minister faces an uphill battle to retain office, with polls indicating Labor is on track to win government on May 21.

Opposition Leader Anthony Albanese on Saturday accused the prime minister of playing short-term politics by not briefing Labor on a plan to build nuclear submarines with the help of the US and Britain until just before it was made public.

Citing a report in The Sydney Morning Herald and The Age, Mr Albanese said the US had requested the Australian government secure support from both major political parties for the plans. The Labor leader said the delay showed that the prime minister is more concerned with politics than the national interest.

"When the request came in, I should have been briefed," Mr Albanese said.

The government's diplomatic credentials became a live election issue after China struck a new security pact with the Solomon Islands in a region Australia and its allies, including the US, have played a dominant role in international relations.

Separately, China has urged Australian politicians to stop being alarmist after Defence Minister Peter Dutton said a Chinese warship sighted off the West Australian coast was an "act of aggression".

Mr Morrison later clarified the ship was only sighted about 250 nautical miles off the WA coastline and it did not enter Australian waters.

The Labor leader focused his campaign on Saturday on the traditionally strong Labor platform of health, with a $750 million pledge to boost Medicare across the country to deliver better healthcare and access for patients.

The Strengthening Medicare Fund would provide $250 million a year over three years from 2023/24, and would seek to deliver more affordability for patients and provide better management for complex and chronic conditions.

Labor would also set up a strengthening Medicare taskforce that would be chaired by the health minister and bring together policy leaders in health, such as the Australian Medical Association.

A grants program of $220 million would be spent on GP clinics to upgrade systems, purchase equipment and upskill staff, with grants of $25,000 or $50,000 available for practices, depending on their size.

Mr Albanese, who campaigned on Saturday morning in Darwin, as Labor seeks to retain the Northern Territory's two federal seats, said the grants funds would make it easier for people to see a GP.

"General practice is the cornerstone of the Australian health system," he said.

"Australians trust their GPs. It's a vital relationship in ensuring all Australians get the quality healthcare they deserve."

Australian Associated Press