LONDON - Britain commissioned a report on Thursday on the economic impact of foreign students, part of an increasingly heated debate over whether they should be included in the government's target of reducing migration to the tens of thousands.

Prime Minister Theresa May has been under pressure to drop international students from Britain's immigration figures, which have remained stubbornly high despite her pledge as interior minister seven years ago to reduce them to under 100,000 a year.

High rates of immigration into Britain were a major reason for the vote to leave the European Union last year. But many officials argue that foreign students contribute to the economy.

"There is no limit to the number of genuine international students who can come to the UK to study, and the fact that we remain the second most popular global destination for those seeking higher education is something to be proud of," interior minister Amber Rudd said in a statement.

"We understand how important students from around the world are to our higher education sector, which is a key export for our country, and that's why we want to have a robust and independent evidence base of their value and the impact they have."

Immigration has long been a sensitive topic in Britain. The expansion of the European Union to take in some eastern European countries saw rates jump, which critics said put pressure on public services such as hospitals.

But others argue that immigration helps the economy and a provides a much-needed workforce. By including students in the immigration figures, they say, Britain is failing to acknowledge the contribution they make or that most leave after finishing their studies.

International students make up around a quarter of total immigration, according to official figures. Data released on Thursday showed that net migration to Britain in the year to March 2017 fell by 81,000 to 246,000 people. More than half of those who left were EU citizens.

In a separate report on "What's happening with international student migration?", the Office for National Statistics said: "There is no evidence of a major issue of non-EU students overstaying their entitlement to stay."

Of the 1.34 million nationals from outside the European Economic Area who held visas that expired in 2016/17, 96.3 percent departed before the visa expired, the ONS said in another report.

Another 0.4 percent departed after their visa had expired. Just 3.3 percent were not initially identified as having departed after their leave expired.

"We have always been clear that our commitment to reducing net migration to sustainable levels does not detract from our determination to attract international students from around the world," Immigration Minister Brandon Lewis said.

"Since 2010 we have clamped down on abuse, while increasing the number of genuine students that come to the UK from around the world."