Unity Gain Amplifier?

Best to use a driver chip to drive the coil. When the coil is released from its drive state, it usually creates a voltage spike which can cause circuit damage. If you use a bipolar transistor, as someone else suggested, you'll need a protection diode. These go across the coil of the relay. This way, when it does create a voltage spike when disconnected, the diode will send it in the right direction, and avoid killing something else in your circuit.

I did this using npn transistor (2n2222 or similar) , connected the gate output to the transistor base by 1 k resistor , connect the emitter to the ground , and the two terminals of the relay between the +V and the collector , that will provide the relay with the necessary current to trigger .

There are special High Current logic chips available that might work, if the relay is small, but in most cases you need a Power Transistor to handle enough current for a relay. Don't forget the Flyback diode to keep from blowing up the transistor!!!!!

probably, if it delivers enough current and the voltage is enough to trip the relay

Indeed it will. If you didn't know, the 244 (Locking Gate buffer) is essentially a unity gain amplifier, and most electronic projects use this chip to amplify the current of this signal. If it isn't enough, you should use a Darlington amplifier as well, just remember that it also acts as a NOT gate.