George Clooney has promised to keep up pressure on Brunei after the oil-rich country’s sultan, Hassanal Bolkiah, announced it would not enforce the death penalty for gay sex.

Gay sex remains illegal in Brunei, punishable by up to 10 years in jail.

Clooney said the moratorium on executions was a “huge step forward after a giant leap backwards”, but that “the law to stone their citizens is still in place”. He added: “For my family and me, we simply can’t walk away until this draconian law is no longer on the books.”

Facebook Twitter Pinterest Brunei’s sultan, Hassanal Bolkiah, delivers a speech in April. Photograph: AFP/Getty Images

Clooney led the international outcry against Brunei’s ruling, which incorporated Islamic laws, or sharia, into the national penal code. The measures were published in 2013, and the introduction of the death penalty by stoning for adultery and gay sex was announced on 3 April. The actor first called for a boycott of hotels owned by Brunei as well as appealing to “the banks, the financiers and the institutions that do business with them and choose to look the other way”.

The United Nations has condemned the law. Celebrities including Elton John and Ellen DeGeneres joined in the outcry, while the UK’s Health and Safety Executive and the Police Federation of England and Wales suspended links with the country.

Having defended the introduction of the law in a letter to the European parliament, Brunei announced that the death penalty moratorium would be extended. In a speech, the sultan said: “I am aware that there are many questions and misperceptions with regard to the implementation of the [sharia penal code order]. However, we believe that once these have been cleared, the merit of the law will be evident.”

Clooney responded by saying: “It … sends a very crucial message to countries like Indonesia and Malaysia that there is a cost for enacting these laws. And the cost isn’t folks boycotting their hotels. The cost is that corporations and big banks won’t do business with you. The financial institutions stepping up had a huge impact. Having said that, the law to stone their citizens is still in place. As soon as the pressure dies down they could simply start the process of carrying out executions. So in reference to the boycott, everyone should do what they feel is correct.”