US Secretary of State, John Kerry, arrived in Japan on Sunday on the last leg of a regional tour dominated by tensions on the Korean peninsula.
Mr Kerry flew into Tokyo from Beijing where he and his Chinese counterpart promised to work together to try and persuade North Korea to give up its nuclear ambitions.
The US Secretary of State will be looking to reassure Japan of continuing US support during the crisis.
The BBC reports Japan has been taking precautions ahead of any possible North Korean missile test.
Japan is within range of these rockets and has been taking precautions, including setting up batteries of US-made Patriot anti-missile systems around the capital and sending two warships to the Sea of Japan, with orders to shoot down any missiles fired towards the Japanese islands.
Mr Kerry is holding talks with Foreign Minister Fumio Kishida and on Sunday will meet Prime Minister Shinzo Abe.
Mr Abe has said they must make Pyongyang "recognise that their provocative actions will not benefit them at all".
Japan's Defence Minister Itsunori Onodera said he hoped Mr Kerry's visit would send "a strong message" to North Korea's leaders.
Korean tension not liked by China
Chinese Premier Li Keqiang has told US Secretary of State John Kerry that rising tensions on the Korean peninsula are in nobody's interests.
State television reports that Mr Li said all sides must bear responsibility for maintaining regional peace and stability and be responsible for the consequences.
Foreign minister Wang Yi also said rising tensions are in no-one's interests and called for peace and denuclearisation.
North Korea has threatened nuclear war against the United States and South Korea in recent weeks.
Mr Kerry was in Beijing to urge China to take a tougher line with North Korea over its nuclear and missile programmes.
He said the United States and China have agreed to work together to rid North Korea of its nuclear capability by peaceful means.
State television quoted Premier Li Keqiang as saying:
"All sides must bear responsibility for maintaining regional peace and stability and be responsible for the consequences.
"Disturbances and provocation on the peninsula and regionally will harm the interests of all sides, which is like lifting a rock only to drop it on one's feet."
North Korea has repeatedly said it will not abandon nuclear weapons which it described on Friday as its treasured guarantor of security.
Disarmament talks, involving the two Koreas, the United States, Japan, Russia and China, collapsed in 2008 when the North walked away from an aid deal.
Chinese President Xi Jinping recently said no country "should be allowed to throw a region and even the whole world into chaos for selfish gain".
