North Korea has said its main nuclear complex is fully operational and the country is ready to face US hostility with nuclear weapons "at any time".
Its nuclear weapons are being improved "in quality and quantity", an official quoted by the state news agency KCNA said.
The director of North Korea's Atomic Energy Institute said atomic scientists had "made innovations day by day" to "guarantee the reliability of the nuclear deterrent...as required by the prevailing situation".
He added: "In the meantime, the US anachronistic hostile policy toward the DPRK that forced it to have access to the nuclear weapons has remained utterly unchanged and instead it has become all the more undisguised and vicious with the adoption of means openly seeking the downfall of the latter's social system.
"If the US and other hostile forces persistently seek their reckless hostile policy towards the DPRK and behave mischievously, the DP
The words come a day after Pyongyang's warning that it is ready to launch "satellites" on rockets banned by the west. This would mark the ruling communist party's anniversary in October and could put pressure on the US to resume talks.
The North's National Aerospace Development Administration director said the satellite would be used for weather forecasts, adding that space development is "a sovereign state's legitimate right" and that the North Koreans are "fully determined to exercise that right".
He added that the world will "clearly see a series of satellites soaring into the sky at times and locations determined" by the Workers' Party.
Germany is expecting one million migrants this year - 200,000 more than previously estimated, Angela Merkel's deputy has said.
In a letter to party members, the country's vice chancellor, Sigmar Gabriel, said: "Everything points to the fact that we won't have 800,000 migrants as has been predicted by the Interior Ministry, but one million."
He also called for other EU nations to take their fair share of refugees, and warned a "common European effort" to tackle the crisis is badly needed.
With the Schengen system of border-free travel through much of the continent under increasing pressure, the European Commission is to outline plans to distribute 160,000 refugees across 22 EU member states over the next two years.
Several countries are opposed to the quota policy.
The UK is not involved in the scheme and instead is planning to accept vulnerable and displaced people from refugee camps in nations bordering Syria.
He becomes the nation's fourth leader in a little over two years, but despite division in his party, Mr Turnbull says he will lead a "very strong government".
"There's been a change of prime minister, but we are a very, very strong government, a very strong country with a great potential and we will realise that potential working very hard together," he said.
"This is a turn of events I did not expect, I have to tell you, but it's one that I'm privileged to undertake and one that I'm certainly up to."
Shortly before Mr Turnbull was sworn in, Mr Abbott spoke for the first time since his sudden ousting.
He warned that the persistent volatility in Australia's government could hurt the nation's standing on the global stage.
"Australia has a role to play in the struggles of the wider world: the cauldron of the Middle East and security in the South China Sea and elsewhere," he said.
"I fear that none of this will be helped if the leadership instability that's plagued other countries continues to taint us."
Mr Turnbull later had to meet with his coalition government to thrash out a new agreement with the National Party to replace the one that had been put in place by his predecessor.
Australian media reported that the agreement is thought to contain a series of promises to deliver more for people in rural communities, which make up majority of the Nationals' support.
Many conservative Nationals were upset at the removal of Mr Abbott, who is seen as more right of centre than his successor.
Mr Turnbull maintains some notoriety among the UK Conservative establishment for having been the lawyer who defeated a British attempt to stop the publication of the MI5 expose Spycatcher in the 1980s.
Despite being a Catholic, he is in favour of same-sex marriage and in his first speech to parliament as prime minister said Australians would vote on same-sex marriage after elections due next year.
He is also a staunch republican and led a previous failed campaign to remove the Queen as Australian head of state.
The great trek north goes on unabated. Thousands upon thousands heading for the sanctuary of the west; or at least that is what they hope.
This is already an intercontinental crisis but it could turn into a European catastrophe if previously open borders are shut.
It will leave tens of thousands, eventually perhaps hundreds of thousands, trapped and homeless within the confines of at least five unwelcoming countries. It will be chaos.
Over the past few days I have travelled with the refugees through the entire Balkan corridor that begins at the Greek border with Macedonia. Travelling through Macedonia and Serbia to Hungary and eventually Austria.
The sheer numbers of people walking, taking buses, trains and taxis is quite remarkable. But things could soon go badly wrong if the EU does not sort out a strategy it is legally obliged to observe.
Like it or loath it the European Union has a collective responsibility to deal with this refugee crisis. The UK and Ireland have opt-outs of course, but the rest of the countries do not, and that is now putting unprecedented stress on the Union.
We thought the economic bailout issues were bad. This utterly dwarfs that simply because we aren't just talking about banks and economics.
An issue that involves so many people, and it is millions, means that Europe in its entirety could actually be socially reshaped. This is sort of biblical stuff.
Given the hammering me and my colleagues are taking on social media for simply covering a factual story, it is clear that there is a collective ignorance of simple facts and recent history.
The danger is that any reasoned debate is overshadowed by hysterical Twitter bullying that is not based on anything other than prejudice.
These are REFUGEES not the economic migrants who have been dying in their thousands trying to get to Europe from north Africa. It does not matter how many times the tweeters, the bloggers and the political right insist they are, they are not.
The governments who find themselves at the centre of this storm have themselves to blame.