Myanmar will refuse entry to members of a United Nations investigation focusing on allegations of killings, rape and torture by security forces against Rohingya Muslims, an official has said.

The government, led by Nobel laureate Aung San Suu Kyi, had already said it would not cooperate with a mission set up after a human rights council resolution was adopted in March.

“If they are going to send someone with regards to the fact-finding mission, then there’s no reason for us to let them come,” said Kyaw Zeya, permanent secretary at the ministry of foreign affairs in the capital, Naypyidaw, on Friday.

“Our missions worldwide are advised accordingly,” he said, explaining that visas to enter Myanmar would not be issued to the mission’s appointees or staff.

Aung San Suu Kyi, who came to power last year amid a transition from military rule, leads Myanmar through the specially created position of “state counsellor”, but is also minister of foreign affairs.

Although she does not oversee the military, Aung San Suu Kyi has been criticised for failing to stand up for the more than 1 million stateless Rohingya Muslims in the western state of Rakhine.

She said during a trip to Sweden this month the UN mission “would have created greater hostility between the different communities”. The majority in Rakhine are ethnic Rakhine Buddhists who, like many in Buddhist-majority Myanmar, see the Rohingya as illegal immigrants from Bangladesh.

Some 75,000 Rohingya fled northwestern Rakhine state to Bangladesh late last year after the Myanmar army carried out a security operation in response to attacks by Rohingya insurgents that killed nine border police.

A UN report in February, based on interviews with some of the Rohingya refugees, said the response involved mass killings and gang rapes of Rohingya, and “very likely” amounted to crimes against humanity and possibly ethnic cleansing.

Myanmar, along with neighbours China and India, dissociated itself from the March resolution brought by the European Union, which called for a mission to look into the allegations in Rakhine as well as reports of abuses in ethnic conflicts in the north of the country.

Indira Jaising, an advocate from the supreme court of India, was appointed to lead the mission in May. The other two members are Harvard-trained Sri Lankan lawyer Radhika Coomaraswamy and Australian consultant Christopher Dominic.

Myanmar insists that a domestic investigation – headed by former lieutenant general and vice-president Myint Swe – is sufficient to look into the allegations in Rakhine.

“Why do they try to use unwarranted pressure when the domestic mechanisms have not been exhausted?” said Kyaw Zeya. “It will not contribute to our efforts to solve the issues in a holistic manner.”

An advisory panel headed by former UN chief Kofi Annan is set to propose solutions for the broader issues in Rakhine but has not been asked to investigate human rights abuses.