Trump talks about working with SpaceX and Elon Musk to reach Mars before Jan 2029. There are two launch windows in late 2026 and in late 2028. It is possible to launch outside of launch windows by going with far less payload and far more fuel.
SpaceX Starship with refueling in orbit would be able to have 9-10 kilometer per second delta-V. This is far more than the typical 3.6 kilometers per second of small final stage launched from Earth.
This higher delta-V enables one-way travel times in the 70-90 day range. There needs to be enough fuel left for a landing. Two or more other Fuel loaded Starships can accelerate out and transfer fuel to enable the main Starship to have fuel for landing with a fast transit. There are specific calculations to determine trading payload for extra fuel and reduced travel times while leaving enough fuel for the landing.