PHNOM PENH - The Association of Southeast Asian Nations (ASEAN) has agreed in principle to admit East Timor as the group's 11th member, the bloc said in a statement on Friday, more than a decade after the country requested membership.

The half-island nation, officially called Timor Leste, will also be granted observer status at high-level ASEAN meetings, the bloc said after regional leaders met in Phnom Penh for a summit.

"We...agreed in principle to admit Timor Leste to be the 11th member of ASEAN," the statement said, adding that next steps would include a "roadmap for full membership" to be submitted at next year's summit.

East Timor President Jose Ramos-Horta welcomed the decision, saying a membership would open up his country to wider diplomatic relations with ASEAN's partners, potentially more foreign direct investment, as well as give Timorese wider travel access within the region.

"There will be a lot of pressure on Timorese elites, our own government to work, to deliver, because it doesn't only come with rights and privileges but a lot of burden of responsibility," Ramos-Horta told Reuters.

However, he noted it might take years for East Timor to gain full ASEAN membership and that his administration would have to work on improving their work capacity across the board.

The East Timorese voted for independence from a brutal occupation by neighbouring Indonesia in a 1999 U.N.-supervised referendum, and the country was officially recognised by the United Nations in 2002, making it Asia's youngest democracy.

The resource-rich country of 1.3 million people immediately started the process of accession to ASEAN, but only formally applied for membership in 2011.

(Reporting by Phnom Penh bureau and Kate Lamb in Sydney; Writing by Kanupriya Kapoor and Gayatri Suroyo; Editing by Ed Davies)