Japanese Prime Minister Shinzo Abe has promised to "deal firmly" with North Korea after exit polls suggested he won a clear victory in Sunday's election.

Mr Abe had called an early election for an increased mandate to deal with "crises" facing Japan, including the threat from Pyongyang.

Local media report Mr Abe's ruling coalition has retained its two-thirds majority in parliament.

This paves the way for Mr Abe to amend Japan's post-war pacifist constitution.

The prime minister has previously called for the existence of the country's armed forces to be formalised, a controversial move which he says is needed to strengthen Japan's defence but which critics say is a step towards re-militarisation.

Speaking after the exit polls, Mr Abe said: "As I promised in the election, my imminent task is to firmly deal with North Korea.... For that, strong diplomacy is required."

The BBC's Rupert Wingfield-Hayes in Tokyo says Mr Abe's victory is partly thanks to Pyongyang's actions.

Just two months ago his popularity was plummeting as he was caught up in two messy political scandals, says our correspondent, but he enjoyed a sudden recovery after North Korea fired two missiles over the Japanese island of Hokkaido in recent months.

BBC