US President Barack Obama has warned Russia of "costs" if it got involved militarily in the Ukrainian crisis.

Since last week's toppling of President Yanukovych, tensions have escalated in Russian-majority Crimea. Reports suggest around 2,000 Russian troops have moved into the peninsula as the acting Ukrainian President Oleksander Turchynov  accused Russia of trying to provoke an armed conflict.

Obama commended the interim government for showing restraint.

“The wanton destruction and violence against civilians in this conflict is shocking.”

“Those wishing to derail the political transition will face swift and firm consequences through the new sanctions committee.”

Around 40 asylum seekers have started a hunger strike at the Manus Island detention centre, where those who arrive in mainland Australia are now being sent to, in protest at the death of a 23-year-old Iranian man killed last week.

US Secretary of State John Kerry declared that any military or government official who conducted or oversaw wartime sexual violence would be refused a US visa, at a discussion held at Washington DC yesterday.

Speaking alongside UK Foreign Secretary William Hague, who has been campaigning on sexual violence, Kerry stated,

“Today, we’re making certain something additional; even though we’ve been aware of it, we haven’t sent yet an embassy-wide message, which I am sending today, that no one, and I mean no one at the highest level of military or governance, who has presided over or engaged in or knew of or conducted these kinds of attacks, is ever going to receive a visa to travel into the United States of America from this day forward.”

“We’re not going to allow that. (Applause.) And every embassy will engage – every embassy and post will be alert to this and to report any of these kinds of incidences, but most importantly there has to be a price attached, and that’s one of the things we need to do.”

The panellists were joined by United Nations Special Representative on Sexual Violence in Conflict Zainab Bangura and Ambassador-at-Large for Global Women's Issues Catherine M. Russell, who was recently refused a visa herself, to enter Sri Lanka earlier this month.

See the full discussion and transcript of the event here.

The US will unveil plans to cut the country’s army as part of cost-cutting measures, reported the New York Times.

The Pentagon is expected to reveal cuts that will downsize the US army to the smallest size it has been since after World War II.

This weekend saw a renewed eruption of clashes between the South Sudanese government and opposition forces, with reports of over 100 dead according to UN peacekeepers.

Reports indicate that Duk County and Gadiang saw heavy fighting, with more than 100 bodies scattered around the roads of Malakal according to UN peacekeepers.