1. I did not search for that news, it was on the headline of news.
2. The news says that your country is going to have a war with Iran soon.
3. America has been asking all other country that used to buy oil from Saudi Arabia to buy oil from America.
The sentences are fine, but here are just a few other suggests:
1. I did not need to search for that news, it was today's headline news story.
1b) 1. I did not search for that news, it was today's leading story.
2. The news REPORT SUGGESTS that your country is going to have a war with Iran soon.
3. America has been asking all of the countries that used to buy oil from Saudi Arabia to now buy oil from America.
Hope that helps
Kind regards
Ryder