It's always tricky to do conclusions.

Basically they are like the end of a conversation with a friend -  when you are finishing a long conversation and getting up to go, you usually talk about the future (what you will do or where you will go next, and maybe wish the other person luck with something that you have been talking about). You won't usually suddenly launch into a new topic, because that would mean you would have to sit back down again and have another cup of coffee or whatever.

So in the case of this essay topic - 'Does foreign aid help donor countries more than the recipients?' - you are probably going to just summarize, as you did in the first sentence here:

In conclusion, conflict of interests can arise when aid is provided to a country by another. A potential solution is letting a neutral third party, like the United Nations, handle the aid program.

...and look to the future (as you did above with your UN suggestion) but perhaps give your general opinion, rather than specific new information....

In conclusion, conflict of interests can arise when aid is provided to a country by another. It's unfortunate that when so much help is needed in the world, it often comes with so many strings attached. Perhaps new, neutral systems for delivering aid would solve the problem, but the important thing to make sure is that aid is for the benefit of the recipient, not the donor.

As you can see, I haven't done any better than you with the conclusion!

I always wondered how you do the future outlook thing or suggest a solution in the conclusion without introducing new ideas...

Aha! I knew something was missing. Now the word count is perfect, at a total of 290 words.

You have given a one-sided response to the question, which is absolutely fine -  your ideas are fully developed. 

In these last two paragraphs, just a couple of points

• donator ==> donor

This sentence is a fragment:

 For example, promoting its own ideological, religious or political views.

One way to fix it is to join it to the previous sentence:

The donor may aim more or less openly for political influence in the target country, for example by promoting its own ideological, religious or political views.

Be careful not to add new information or ideas in the conclusion, like your one about the United Nations. New ideas belong in the body where they can be fully developed.

Thanks for adding the missing paragraphs! 

The donator may aim more or less openly for political influence in the aided country. For example, promoting its own ideological, religious or political views. Moreover, providing aid can support an incompetent and corrupt governments in a recipient country that otherwise would fail to ensure the basic needs of its citizens are met.

In conclusion, conflict of interests can arise when aid is provided to a country by another. A potential solution is letting a neutral third party, like the United Nations, handle the aid program.

Some more great ideas and sentences.

Did you leave out the conclusion? It's only 204 words -  and you know you need 250 minimum. 

I love your introductory sentence:

Foreign aid programs have been criticized for profiting the donor country over the recipient country.

Plurals/Possessives

this type of aid is always tied to a donor countries interests and stakes in the recipient country ==>

this type of aid is always tied to a donor country's interests and stakes in the recipient country

Aid can further damage a countrie’s weak economy ==> Aid can further damage a country's weak economy ==>

In summary:

• One country (e.g. Spain) : The country's economy has suffered in the last few years.
• Two or more countries (e.g. Thailand, Vietnam and Laos): The south-east Asian countries' economies are linked to China's and will benefit from a politically-stable China.

Parallel lists

Possible motives for helping other countries are to secure its borders, allies and access to raw materials or future markets.

Yes, you have worked hard to make it parallel already, but it doesn't feel right. Perhaps using three verbs will help

Possible motives for helping other countries are to secure borders, strengthen political alliances and ensure access to raw materials or future markets.

Foreign aid programs have been criticized for profiting the donor country over the recipient country. While there are positive effects of aid programs, this type of  aid is always tied to a donor countries interests and stakes in the recipient country. Receiving aid may have some negative side effects on the economic and political development of a country.

By aiding a country, the benefactor country may also act in its own interest. Possible motives are to secure its borders, allies and access to raw materials or future markets. For example a country can try to limit immigration from a poor neighbouring country by providing aid. Additionally, it may aim to improve its image by aiding another country.

Moreover, the economy in a beneficiary country can become fully dependent on imported aid goods, as aid can further damage a countrie’s weak economy. Imported goods may weaken the demand for locally produced goods that may be unable to compete with quality and price of the imported goods. Long term this can lead to a loss of skills in a country being used to be given goods instead of producing them. At the same time producing aid goods can help the domestic economy in the donor country.