India, Indonesia, Myanmar, Pakistan and Papua New Guinea account for 89 percent of the 30 million malaria cases in the region, with India home to some 22.5 million cases, according to the report by the World Health Organization (WHO).
In these countries, health systems are weak and under-resourced, with government spending on health less than $32 per person per year, and as low as $2 in Myanmar and $7 in Pakistan, the WHO notes.
"They need substantial financial resources and technical assistance to strengthen their health systems before they can visibly improve their malaria response," says the report, produced for the Roll Back Malaria partnership, the global framework for coordinated action against malaria.
"At their current pace, it is unlikely that these countries can achieve the malaria-specific Millennium Development Goals and the World Health Assembly target of reducing the malaria burden by at least 75 percent by 2015."
Across the region, indigenous people, ethnic minorities, migrants and forest workers, as well as communities living in border areas are most exposed to infection, the report notes.
Another major worry in Asia is emerging resistance to artemisinins, which are central to the efficacy of antimalarial treatment, it says. Artemisinin resistance has been detected in Cambodia, Myanmar, Thailand and Vietnam.
Experts fear it could threaten the world's fragile gains against malaria in the last decade, if it spreads or appears independently in other regions.
"Antimalarial drug resistance is one of the greatest challenges to continued success in controlling and eliminating malaria in the Asia-Pacific," Robert Newman, director of WHO's global malaria programme, said in a statement.
"It will be critical to galvanise political action and secure investments to implement an emergency response plan for the Greater Mekong subregion," he added.
The report - the first to analyse the fight against malaria outside Africa - notes that while the African continent carries the major burden, the disease also affects 51 countries in other parts of the world. There are 20 countries with ongoing malaria transmission in Southeast Asia and the Western Pacific, 21 in the Americas, and 10 in the Eastern Mediterranean and Europe.
Malaria - a preventable and curable disease transmitted to humans by mosquitoes - caused an estimated 655,000 deaths worldwide in 2010, mostly among African children, with 46,000 of those outside Africa, according to the WHO. Around 216 million malaria cases still occur in the world every year.
International funding for malaria control outside Africa rose from less than $17 million in 2000 to $300 million in 2010, according to the report. That has improved coverage of preventive measures, such as insecticide-treated nets and indoor spraying, as well as diagnostic testing and treatment.
As a result, malaria mortality rates have decreased by 30 percent outside Africa, and 34 of the 51 countries have reduced their cases by more than half. But the report emphasises that more populous countries with higher disease burdens, including Bangladesh, India, Indonesia and Myanmar, have seen slower progress.
Part of the problem is that funding is still inadequate to reach global malaria targets and provide universal access to prevention and control measures - which would require $3 billion for Asia-Pacific alone, the report says.
At a conference this week in Sydney on malaria in the region, government ministers and malaria experts, among others, have called for political leadership to strengthen the response.
"Our focus must be on cross-regional action alongside traditional single-country strategies. Today's meeting is an opportunity for Asia-Pacific leaders to coordinate efforts in controlling or eliminating the spread of malaria,” said Bob Carr, Australia's minister for foreign affairs.