A spokesman for UN Secretary-General Ban Ki-Moon has said that any violation of the ceasefire agreed today would be "utterly irresponsible".
He said the blockade of Gaza must end, and that the territory must be brought back under the control of one legitimate Palestinian government adhering to Palestine Liberation Organisation commitments.
"Israel's legitimate security concerns must be addressed," he added.
Three member of a UN peacekeeping helicopter crew that crashed in South Sudan have died, the UN said. One survivor is being treated.
The cause of the crash remains unclear.
The UN Mission in South Sudan has said that one of its helicopters has crashed close to the small town of Bentiu in Unity State.
UNMISS said it was "deeply concerned about fate of crew".
UNMISS deeply concerned about fate of crew, has dispatched a search & rescue team to site of incident.
The UN Human Rights Council is set to hold an emergency session on Wednesday on the situation in Gaza following a request by Egypt, the United Nations has announced.
Insurgents in northern Iraq have seized nuclear materials from Mosul University, according to a letter from an Iraqi ambassador to the United Nations.
The letter appealed for UN help to "stave off the threat of their use by terrorists in Iraq or abroad" after around 88 pounds of uranium compounds were apparently seized.
In a letter obtained by Reuters, Iraq's UN Ambassador Mohamed Ali Alhakim told Secretary-General Ban Ki-moon on July 8: "Terrorist groups have seized control of nuclear material at the sites that came out of the control of the state."
He added that the nuclear materials could "be used in manufacturing weapons of mass destruction" and warned they could also be smuggled out of Iraq.
The materials were not believed to be enriched uranium and therefore would be difficult to use in manufacturing a weapon of mass destruction, a US government source told the news agency.
Russia has called an emergency meeting of the United Nations' most powerful body, seeking an immediate halt to the deadly clashes in eastern Ukraine - after months of blocking any Security Council action.
Russian foreign minister Sergey Lavrov said Moscow now wanted Security Council action to end weeks of violence in Russian-speaking eastern Ukraine between government troops and pro-Russian insurgents, a move immediately denounced by the United States as "hypocritical".
A child abuse activist and survivor is "positive" the Catholic Church's body investigating allegations of clerical sexual abuse will be more than just "a talking shop".
Marie Collins, who sits on the investigative board, was speaking ahead of the Holy See's testimony in front of the UN's torture committee into the church's handling of the sexual abuse crisis.
We are coming from very different perspectives but we all have one aim in mind, the protection of children and . . . I am happy at the moment that the meeting is addressing the issues I hoped it would address.
The Catholic church will find itself back "in the dock" as it is due to testify before the Committee Against Torture in Geneva.
Last February the UN Committee on the Rights of the Child issued a damning report of the Catholic Church’s handling of its clerical sex abuse crisis, accusing it of being more concerned with protecting its reputation, than it was with looking after children.
More sex abuse victim groups have come forward in the US and submitted fresh claims, it has emerged.
The Catholic Church has criticised the UN's decision to include child abuse allegations at a hearing on torture.
Vatican spokesman Fr Frederico Lombardi rejected the attempt “to bring the issue of the sexual abuse of minors into the discussion on torture” rather than into child protection.
Laura Bates, the author of Everyday Sexism, has told ITV News that the UK is "quick to point to other countries" over sexist behaviour, after the a UN investigator denounced the country's "boys' club sexist culture".
Ms Bates said that the report shone a light on the "spectrum of abuse".
Sexism in the UK is more pervasive and "in your face" than other countries, a United Nations (UN) investigator has claimed.
UN special rapporteur on violence against women Rashida Manjoo said there is a "boys' club sexist culture" in Britain that influences perceptions of women and girls.
Following a 16-day visit to Britain, Ms Manjoo also warned Government cutbacks have hit violence-against-women services and confirmed reports she was blocked from entering controversial immigration detention centre for women, Yarl's Wood.
In an initial report on violence against women, the South African human rights expert said legal and policy responses focused on harmful practices, such as early and forced marriages but ignored the harms coming from a "a sexist culture that exists in the country".