NHK Easy

 アメリカとウクライナは、ウクライナの資源を一緒に開発することを決めてサインしました。

What I understand from this sentences is that America and Ukraine together did something regarding minerals. After some dictionary use found that they came together to agree the block of imports of minerals from Ukraine.

アメリカは、2つの国がお金や人を出して,

From my understanding this sentence is saying that America as a country has already submitted two resources Money and People. 

被害を受けたウクライナの経済や生活をよくすると言っています。

What I originally understood from this sentence is that they are often saying that Ukraine can something. After dictionary use I understood that they are currently saying that with the help of the resources America has already given (sentence above) Ukraine can fully recover economically after the disaster.