An aid flotilla carrying food and emergency supplies for Rohingya Muslims is to sail from Malaysia for Myanmar's Rakhine State in January.
Zulhanis Zainol, secretary-general of the Malaysian Consultative Council of Islamic Organisations, said on Friday that the coalition organising the flotilla had applied for permission to enter Myanmar through its embassy in Kuala Lumpur, but had yet to receive a reply.
"Even if we do not receive a response, we will continue to sail as we believe this is an important humanitarian mission," he said.
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Malaysia has been an outspoken critic of the Myanmar government's handling of a violent crackdown in Rakhine, which has killed scores of people and displaced 30,0000 Rohingya, amid allegations of abuses by security forces.
No non-Myanmar citizens can enter our body of water without our permission. If they do, we will respond - we will not attack them, but we will not receive them
Myanmar's presidential office denied it had received a request and said it would not accept the flotilla's arrival without prior permission.
"If they are looking for trouble, we will not accept that," Zaw Htay, spokesman for the presidential office, told Reuters news agency.
"No non-Myanmar citizens can enter our body of water without our permission. If they do, we will respond - we will not attack them, but we will not receive them."
The flotilla, departing from Malaysia on January 10, would be carrying 1,000 tonnes of rice, medical aid and other essentials for the Rohingya population.
Earlier this month, Malaysia urged the Association of South East Asian Nations (ASEAN) to coordinate humanitarian aid and investigate alleged atrocities committed against Rohingya Muslims.
Both Malaysia and Myanmar are members of the 10-nation grouping, which has a long-standing policy of not getting involved in each other's internal affairs.
An estimated 150,000 to 200,000 Rohingya, displaced by previous violence, live in Malaysia.
Myanmar has previously said that access to Rakhine for humanitarian assistance would be open, but certain Rohingya communities have remained off-limits to aid agencies on security grounds.
Source: News agencies