Europe markets seen lower; Greece, oil eyed

European equities are expected to open lower on Wednesday with investors keeping an eye on the Greek prime minister's visit to Moscow and the drop in oil prices.

Greek Prime Minister Alexis Tsipras is in Moscow to meet Russian President Vladimir Putin on Wednesday. The meeting comes as both leaders face increasing isolation in Europe – Tsipras for his country's economic crisis and Putin for his country's annexation of Crimea and part in the conflict in east Ukraine.

Speculation has mounted that Russia could offer Greece financial aid but officials in Europe are worried any aid offer could be used to secure a Greek veto against any new European sanctions on Russia.

In Asia news, Japanese stocks hit 15-year highs on Wednesday after the Bank of Japan (BoJ) kept its massive monetary stimulus intact as expected. The central bank also reiterated that the world's third-biggest economy is recovering moderately.

Elsewhere in the region, markets were seemingly unaffected by the weaker finish overnight in the U.S. as investors eyed continued gains in oil and the U.S. dollar ahead of the unofficial start of earnings season on Wednesday.

In corporate news, investors will be watching for more news after the Wall Street Journal reported late Tuesday that oil giant Royal Dutch Shell was in advance talks to acquire British natural gas group BG in a deal that would likely be valued at upward of $50 billion.

In commodities news, oil prices fell more than a percent on Wednesday as industry data showed a larger-than-expected weekly build in U.S. stockpiles and as Saudi Arabia reported record output in March, Reuters reported.