BRUSSELS (Reuters) - Ursula von der Leyen pledged on Thursday to revamp border management, strengthen Frontex and Europol, and to put forward a new approach for the return of migrants, if she wins a second five-year term as head of the European Commission.

In a 31-page document setting out her vision, before EU lawmakers vote to elect or reject her later on Thursday, she said she will propose to triple the number of European border and coast guards to 30,000.

"We will show no tolerance for those who threaten the security of our borders and our citizens with hybrid attacks," von der Leyen said.

"Hostile actors who push people across the EU's external borders for political purposes should be recognised as a threat to our security and should be sanctioned."

Von der Leyen added she will appoint dedicated commissioners for EU enlargement and for relations with the Mediterranean.

(Reporting by Marine Strauss, editing by Bart Meijer)

By Marine Strauss