Waning patience over repeated failure of ceasefire agreements prompts US to propose global travel ban and asset freeze

Scathing report by parliamentary group warns government must reevaluate its strategy for helping children affected by conflict

Juba government condemns killing of Carter Center employee ‘in the strongest terms possible’

A British aid worker was killed on Tuesday night in Juba, the capital of conflict-riven South Sudan, the Foreign Office has confirmed. According to reports, the victim, who has not been named, worked for the Carter Center, the NGO set up by the former US president Jimmy Carter.

A spokesman for the South Sudanese government said the man appeared to have been deliberately targeted as he returned to his compound in Juba.

UN humanitarian chief supports international action during visit to rebel-held area with American actor Forest Whitaker

Valerie Amos has joined calls for an arms embargo against South Sudan, the most senior UN official to back growing international demands for action against the country as it enters a second year of civil war.

“Anything that takes weapons off the streets, out of countries and out of communities will help us because ultimately for us it’s about bringing peace,” the UN humanitarian chief told the Guardian. “If there are no weapons, it’s harder for people to fight, peace will come sooner and we can get more aid to the people who so desperately need it.”

In 2014, we covered pollution from Mexico City to Manila, corruption in Mali and the Ebola crisis in west Africa. But what happened next? Hugh Muir talks to our reporters to find out

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As part of our week-long focus on the Sudans we opened up conversation to our readers. Here are some of our highlights of what you told us

• Sudan is hungry for change, but who will take on Omar al-Bashir?