Building stronger defence and security ties will be at the centre of the Prime Minister's agenda in formal bilateral talks with Singapore today.

Closer military cooperation and improving the 2003 free trade deal between the two nations will feature in the talks.

But before the formal discussions begin, Tony Abbott has been wielding Australia's diplomatic soft power in Singapore — with barbecues.

Last night, Australia put on barbecues around the island nation to mark the 50th anniversary of diplomatic relations between the two countries.

"Fifty barbecues that the Australian High Commission has organised to celebrate 50 years of Singaporean independence," Mr Abbott explained to one curious local.

Singapore's prime minister, Lee Hsein Loong, joined Mr Abbott at the largest barbecue in Bishan Park, where hundreds of Singaporeans and Australian expatriates tucked into steaks and fried rice.

The pair embraced the carnival atmosphere, manning the grills, donning balloon hats, trying their hands at drumming and posing for countless selfies.

They chatted jovially about everything from the weather to social housing to managing multi-faith communities.

It was a successful display of diplomatic soft power by Australia, ahead of the hard talks.

Today, Mr Abbott will meet president Tony Tan at the presidential palace and hold a bilateral meeting with Mr Lee.

Security, investment and free trade on the agenda

On the economic front, Mr Abbott wants to upgrade and expand the 2003 Singapore-Australia free trade agreement.

He also wants to convince Singaporean investors to fund infrastructure development in northern Australia.

"We have space, we have resources. They have services, they have capital," he said.

"I think the complementarity between our two countries are as strong as between any two countries in the world. Let's build on those."

The security agenda is broad, ranging from territorial flashpoints in the region to sharing counter-terrorism information.

"Given the state of the world right now, it's more important than ever that those of us who stand for decency and justice stand together and learn from each other."

Peter Jennings, the executive director of the Australian Strategic Policy Institute, said the two countries were close and becoming even closer.

"The way Australia and Singapore cooperate together is very effective and it has been for decades," he said.

It is a stark contrast to Australia's strained relations with Indonesia, but Mr Jennings said he believed Singapore has difficulties with Jakarta, too.

"The honest assessment is that Indonesia presents a challenge, not only for Australia but also for Singapore."

He said Singapore would be disappointed that "Indonesia, under President Jokowi, is inward-looking and not really being able to play a significant leadership role within ASEAN or responding to things like increasing problems in the South China Sea".

"That's going to drive Australia and Singapore into even closer forms of cooperation."