Brazilian President Michel Temer has promised next month's Olympic Games will show the world "one of the major global economies at work in a mature democracy" in a special welcome message designed to alleviate growing fears with just 30 days to go until the Opening Ceremony of Rio 2016.

Temer, who replaced Dilma Rousseff on an interim basis in May pending her ongoing impeachment trial, addressed the various challenges of transport, venue completion, security and public support in a bulletin circulated in English, French and Spanish, as well as Portuguese.

He also sought to downplay the risks of Zika virus during the Olympics, which are due to open on August 5.

Temer first addressed security concerns, which are fast becoming the biggest challenge after a tumultuous few days in which, among other problems, police have been on strike and part of a dead body was washed up on Copacabana Bay.

"With 30 days until the world’s greatest sporting event is scheduled to begin, Brazil can say with confidence: we are ready to host the first Olympic and Paralympic Games to take place in South America," Temer said.

"The country has put together a solid security programme of 85,000 Federal, State and Municipal Government personnel to ensure that sporting events take place in an atmosphere of absolute peace and tranquility.

"This contingent of security personnel will work in an integrated fashion, overseeing the protection of athletes, coaching staff, heads of state, Government officials, local residents and journalists.

"This will not be Brazil's first opportunity to show the world its capacity for organisation, and to welcome visitors warmly to a secure environment.

"Over the past few years, our country has developed an expertise in hosting mega-events on an international scale.

"We hosted the World Cup, the Pan-American Games, the World Military Games, World Youth Day and the Confederations Cup - all unanimous successes, which we conducted in a spirit of excellence, dedication and with the characteristic Brazilian joie de vivre.

"And now, another success is on its way."

Temer claimed that the Olympic and Paralympics has boosted the economy and helped speed-up the construction of new facilities including the subway due to link the city centre with the main Games hub at Barra de Tijuca.

"The Games will show the world one of the major global economies at work in a mature democracy: a country with great business potential that at the same time has set the standard for policies to fight inequality," he said.

"Rio de Janeiro is expected to receive hundreds of thousands of visitors from Brazil and abroad during the Games, while the five 'Football Cities' - São Paulo, Salvador, Manaus, Brasília and Belo Horizonte - will also find themselves inundated with local and foreign fans.

"Hosting events on this scale represents both a momentous accomplishment for the Brazilian people and a source of immense national pride.

"Finally, in Rio de Janeiro, the Games have greatly influenced the implementation of public policy, causing the city to fast track, expand and even initiate many municipal infrastructure and mobility projects.

"The direct, favourable impact of these policies on the quality of life of the city’s residents is evident."

These claims can be challenged, however.

Rio de Janeiro Mayor Eduardo Paes this week criticised the State Government - who will still play a role during the Games - for the "terrible" and "horrible" security job they have done.

Others have doubted there will be as many as 85,000 personnel, while it is not clear where many of these additional security staff will stay during the Games.

Public enthusiasm for the Games is mixed, with a Facebook post and a video, seen below, of a teacher ripping up her tickets in protest at the city's economic problems having been circulated widely on social media.

Many think the Games-time spending is unsustainable at a time of such economic and political misery.

It remains possible the impeachment trial of Rousseff could also conclude during the Olympics, which would exacerbate fears of protests and wider discontent.

Twenty per cent of tickets remain to be sold, organisers have also said this week.

Temer also minimises the impact of Zika, which has been linked with a condition in which babies are born with small heads and under-developed brains.

This has prompted several athletes - primarily golfers - to withdraw from the Olympics, although organisers insist the risks of contracting the mosquito-borne disease are low in the Brazilian winter.

"I recall a similar prediction of epidemic during the 2014 World Cup tournament in Brazil, when we hosted 1.4 million foreign visitors - no epidemic occurred," Temer said.

"Then as now, tourists can be assured of favorable health conditions during the Olympic Games.

"Brazil is ready to receive all of the visitors who will be enjoying the pleasure of watching the world's elite international sports athletes compete, and, surely, we will have a great deal to show the five billion viewers from around the world who will be watching the Games as well."