They say it'll do nothing to stop the abuse of Indonesian domestic workers, and will only drive the trade underground, exposing them to even greater risks.
"(It's) a very desperate move after the government refused to provide genuine and necessary protection for their overseas domestic workers," said Eni Lestari, chairwoman of the International Migrants Alliance (IMA), which has more than 150 member organizations in 35 countries.
Indonesian President Joko Widodo foreshadowed the move in February by announcing that he wanted to put an end to the export of the country's female workers.
"The practice of Indonesian women going overseas to work as housemaids must stop immediately. We should have pride and dignity," he was quoted as saying.
Indonesia maids executed
The government is wary of the safety of its citizens working abroad, particularly in countries in the Middle East, which has a poor record when it comes to the rights and treatment of foreign workers.
Since Widodo's remarks, Saudi Arabia, one of the largest destination countries for Indonesia domestic workers, has executed two maids who were on death row for murder.
Indonesia expressed its anger over the beheadings, and summoned the Saudi ambassador for talks, with the main complaint being that Indonesian officials hadn't been notified of the timing of the executions.
The two women -- Karni Bt. Medi Tarsim, 37 and Siti Zaenab Bt. Duhri Rupa, 47
-- were both convicted of murder in two separate cases but rights groups cast doubt on their convictions and had appealed for them to be spared.
21 countries banned
On Monday, Indonesia's Minister of Manpower Muhammad Hanif Dhakiri said the country was trying to protect its workers from countries with inadequate labor laws.
"The most important reason is there are no standardized labor regulations that bind the said countries, to the detriment of migrant workers," he said.
The banned countries are: Algeria, Saudi Arabia, Bahrain, Iraq, Iran, Kuwait, Lebanon, Libya, Morocco, Mauritania, Egypt, Oman, Pakistan, the Palestinian territories, Qatar, South Sudan, Syria, Tunisia, the United Arab Emirates, Yemen and Jordan.
According to the Ministry of Foreign Affairs, more than 630,000 Indonesians work in the Middle East. However, the government says that could be as high as 1.8 million when illegal workers are taken into account.
The Indonesian government has laid some of the blame on the situation on the "kafalah" system in some Middle Eastern countries, which ties workers' visas to sponsorship from their employers.
"This culture often leads to migrant workers becoming highly dependent on their employers. It also weakens their position, their working condition and lives," Dhakiri said.
The ban will be brought in over a transition period of three months. Around 4,700 domestic workers in the process of being employed in the Middle East will still be allowed to travel, Dhakiri said. But he added that they'll be the last. Maids who are already there will be allowed to finish their contracts.
Lestari, from the International Migrants Alliance, said the official ban wouldn't stop domestic workers who are determined to work abroad from entering banned countries.
"It doesn't minimize (the problem). If fact, it puts all people in a very dangerous situation," she said, predicting that workers currently in those countries would overstay their visas in order to remain employed.
She blamed the current situation on the Indonesian government, which she said had failed to offer adequate protection and advice to workers in foreign countries.
"We believe that the reason why the government has committed to stopping the deployment is simply because there are too many cases that haven't been properly responded to by the government."
Lestari said not enough was going down to punish unscrupulous recruiters, who she said were likely to keep sending workers to the Middle East despite the ban.
Millions of Indonesian migrant workers are employed by foreign countries, and in 2013 they sent home remittances worth more than $7.3 billion
They choose to work away from their families because there are fewer job prospects at home.
The Indonesian government said it would endeavor to create more opportunities for workers to stay in Indonesia, by providing entrepreneurial training.
"The government also will shift these would be migrants to be legally employed in the formal sector, based on their capabilities and competencies," Manpower Minister Dhakiri said.