SINCE Buhari's victory at the polls several countries have shown a renewed interest in Nigeria and have moved to improve ties with the incoming administration.
The US had expressed concern over series of issues. One issue relates to the massive human rights abuses by the Nigerian military in its prosecution of the war in the North-east. The second issue the US has expressed concern about is the manner top officials of the Nigerian Government have managed the Oil and Gas sector of the economy, citing several acts that bothered on corruption.

A source in the foreign ministry said the US is now eager to turn the situation around, as it has always considered Nigeria an important ally on the African continent. Several highly placed persons and multinational companies who attended a US State Department briefing cited corruption as the main reason for low investment in Nigeria's oil sector. It is understood that the US is backing a senior official of a multi-national oil company from Delta State who is conversant with transparency rules to emerge as the Petroleum Minister.

Read More:http://www.nationaldailyng.com/news/latest-news/4015-us-lobbies-buhari-on-petroleum-minister

USA are not willing to buy the oil, so the investment is simply to take advantage of our incompetent government. I am really sceptical of USA motive.
Perhaps, that will throw some light into why they supported GMB aggressively.

I thought US no longer buy our oil, why are they pokenosing into our oil industry?

The U.S should back off! Buhari and his ape.pc team have made a promise to deliver change to nigerians. we are waiting for the change... *watching with fingers crossed*

Wetin concern them?

They are just playing their role as a leader