Urgent tasks create interruptions and distract you from your real goals. The urgent is focused on the short-term whereas the important things should be related to the achievement of your goals. If you regularly are confronted with urgent matters that suddenly pop-up, you first have to analyze the source of these urgent tasks:
One major source of urgent matters can be your own procrastination. Some people feel an excitment when they have to complete something on the last minute even if they had all the time to prepare things in advance.
If this is true for you, there is a choice to be made. In case you are happy with this situation, don’t change it - it will not work anyhow.
If you feel bad about this most of the time, you have to apply techniques to manage your procrastination. In the first step you need a proper to-do list. Then you schedule time slots in your calendar to work on the tasks you typically procrastinate. Even if you cannot complete them during this time the progress makes it easier to restart the next time. It is also important that you put away all possible distractions and also reward yourself once you completed the task.
2) Other colleagues
If urgent tasks mainly come from other colleagues you need to openly address this. They keep interrupting you and reduce your overall productivity. This behavior makes it impossible for you to plan your own tasks. Rather than blaming your colleague it is better to explain why these urgent matters are difficult to handle for you. When he understands your situation you can come up with a proposal on how you can even better support in case you receive the requests or information earlier.
If this does not work at all and you have a feeling that your colleague does not care there might be no other way than using an urgent but not so important matter and let your colleague wait. Just make sure that it does not impact a customer.
3) Your boss
If you boss permanently interrupts you with urgent tasks you need to improve your communication. Propose a regular meeting where you discuss upcoming tasks. This should help reducing the number of urgent items coming up suddenly.
You also have to understand the difference between urgent and important. There are tasks that might be urgent but not important. In general I recommend giving the important task a higher priority than the urgent but unimportant task.