The problem of vehicle-target assignment (VTA) to capture a team of evading targets using a swarm of pursuing vehicles is investigated in this article. The VTA problem is formulated as an integer linear programming (ILP), such that the time to intercept all the targets is minimized subject to a number of constraints. To obtain closed-form formulas for the time-to-go matrix in the framework of ILP optimization, a one-on-one pursuit-evasion problem based on the ideal proportional navigation (IPN) guidance law is investigated. By considering two different scenarios of non-maneuvering and maneuvering evaders, analytical closed-form solutions for the pursuit-evasion time-to-go as explicit functions of the position and velocity vectors of the pursuers and evaders are developed, and efficient evasion strategies based on IPN guidance scheme are presented. The efficacy of the theoretical results in estimating the elements of time-to-go matrix is demonstrated by solving the VTA problem in simulations.