Languages such as Arabic, Bengali and Mandarin should be given higher status in England's schools to enable more pupils to learn them, Ofsted says.
Language study at GCSE is declining
"Community languages" should have the same status as French, German and Spanish, the education watchdog said.
It criticised the teacher training system, warning that most "community language" teachers were not qualified.
Ministers say they will work with training providers to widen the number of trainee teachers of world languages.
Last year Lord Dearing's report for the government on languages said it would be crucial to teach more community languages, particularly because of economic growth in China and India.
But the numbers of pupils taking community languages - and other languages - continue to fall.
Pupils no longer have to study a modern foreign language after the age of 14.
Ofsted inspectors said training for teachers of community languages should be improved and more invested in resources for schools to help in the teaching of such languages.
Miriam Rosen, director of education at Ofsted, said: "We found that people want to have the opportunity to learn community languages, despite the barriers existing today.
"We also discovered that when community language teachers were given the opportunity to gain qualified teacher status, their teaching improved."
A report from the watchdog said not many students were taking up places on the "limited" postgraduate training courses in community languages.
Ofsted said: "The majority of community languages teachers surveyed did not have qualified teacher status.
"Just over a quarter of them were qualified in the UK to teach languages. Barely a fifth had a postgraduate certificate in education in any subject."
GCSE and A-LEVEL LANGUAGES
French, German, Irish, Spanish, Welsh, Arabic, Bengali, Chinese, Dutch, Gujarati, Italian, Japanese, Modern Greek, Modern Hebrew, Panjabi, Persian, Portuguese, Polish, Russian, Turkish and Urdu
After French, German and Spanish, the most popular languages in terms of the number of GCSE entries are Urdu, Italian and Chinese
The report called for action "to stem the decline in the number of entries for GCSE community languages and to promote them up to and beyond GCSE level".
Schools Minister Jim Knight said: "Everyone in this country should be confident in English but it is vital that they are also confident in other languages, including their mother tongue.
"In order to compete in the global economy, future generations need to be able to speak major world languages.
"That is why we have widened the range of languages that schools offer, acting upon Lord Dearing's recommendations.
"We will be exploring with the Training and Development Agency how we could broaden the number of trainees in world languages."
A spokesman for the Training and Development Agency for Schools said all community languages teachers who were graduates could apply for training to achieve qualified teacher status.
He added: "Teacher training providers are free to offer a wider range of languages than the current core offer of French, German and Spanish. Other languages enjoy equal status".