Voting is underway in France's presidential runoff election between centrist President Emmanuel Macron and his far-right contender Marine Le Pen.

Macron and Le Pen garnered the most votes in the first round of voting on April 10. They faced off in the previous runoff five years ago.

About 70 thousand polling stations across France opened at 8 a.m. on Sunday.

At a polling station in Paris, voters began casting ballots one after another as soon as it opened.

Key issues in the campaign included how to deal with the situation in Ukraine and France's relationship with the European Union.

Macron maintains that the EU should stay united to seek a diplomatic solution to the Ukrainian issue, and he is calling for stepped-up sanctions against Russia.

Le Pen is appealing to those on low incomes by pledging to cut value-added tax in response to soaring fuel prices. She also opposes sanctions that would stop imports of natural gas and petroleum from Russia, saying this would further depress the economy.

In a poll taken on Friday, 55 percent of the respondents said they would vote for Macron, while 45 percent said they would vote for Le Pen. The difference is much smaller than in the last runoff election in which Macron had overwhelming support.

Vote counting will begin immediately after polling stations close at 8 p.m.