Hammond 'solidarity' with Japan
Foreign Secretary Philip Hammond said the UK stood in "solidarity" with the people of Japan as they face the "appalling" threat from terror group Islamic State (IS).
Mr Hammond met his counterpart from Japan at the Foreign and Commonwealth Office as he and Defence Secretary Michael Fallon hosted the first formal meeting between the two countries on foreign and defence issues.
High on their priorities is the hostage situation in the Middle East, with IS demanding 200 million US dollars (£132 million) for the release of two Japanese hostages.
Extremists have released a video showing a knife-wielding militant stood over the two captives and issuing demands.
Welcoming Japanese foreign minister Fumio Kishida to the UK, Mr Hammond said the meeting symbolised "in a very concrete way Japan's engagement with the international community and the role that Japan is increasingly taking in securing international peace".
He said: "We will of course be talking about the the challenge of dealing with Isil and we will want to discuss in detail the hostage crisis.
"Allow me to express our solidarity with the Japanese people as they face this appalling threat from Isil."
Mr Hammond said they would also discuss how the UK and Japan can work together in responding to international challenges, as well as building on our "already strong" relations.
Describing the UK as Japan's "longest partner", Mr Kishida called on the two countries to work together to fight the scourge of terrorism.
He said: "Japan resolutely condemns deplorable acts of terrorism which we are seeing in the hostage situation by Isil and also the shooting incident in Paris.
"Japan and the United Kingdom can co-operate together to fight against terrorism."
In 2015, the 70th anniversary of the end of the Second World War, Japan has been "greatly contributing to world peace, stability and prosperity, and our path will remain the same as a peace-loving nation", he said.
Mr Kishida added: "Japan and the United Kingdom, both of which have greatly contributed to the peace and prosperity of the world, must and can co-operate together to tackle the challenges that the international community faces together."
The pair will later hold talks with Mr Fallon and Japan's Defence Minister Gen Nakatani at Lancaster House.
The hostage crisis poses a serious problem for Japanese prime minister Shinzo Abe.
He has vowed to save the two men, 47-year-old Kenji Goto and 42-year-old Haruna Yukawa , but with his military operating only in a self-defence capacity at home, Mr Abe faces having to pay the demands or ask an ally to attempt a rescue mission.
He has so far declined to say whether he would pay a ransom, th ough he sent his deputy foreign minister, Yasuhide Nakayama, to Jordan to seek the country's support in resolving the situation.