With EU backing, an ambitious scheme is taking shape for a cross-border metro to link Copenhagen with Malmo. This would almost certainly serve Kastrup airport, between the two.

In addition, Line M5, the former S-Bane line F, is likely to be converted to metro and extended from Ny Ellebjerg (southwest of the city) to Kastrup airport (in the southeast) calling at Islands Brygge on Line M1. Completion could be as early as 2024-2026.

A light rail line is under construction through the western suburbs from Ishøj in the south west to Lundtofte, due north of the city. A branch from the southern end to Brøndby, Avedøre Holme and Kastrup airport is planned.

Copenhagen Metro Line M1
 
IARO Express 82 carried an article with plans for cross-Øresund services
Source:  IARO, Metro Report International

Source IARO, Metro Report International