US Secretary of State John Kerry tweeted on the first anniversary of the Boston Marathon bombings:
One year later, even if you were miles from home, no Bostonian will forget this day. Remember victims, honor heroes. We are #BostonStrong.
Russia and the United States exchanged strong-worded warnings over armed actions in Ukraine today.
Russian Foreign Minister Sergei Lavrov said that any armed action by Ukrainian authorities in the east of the country would undermine efforts at a diplomatic solution to the conflict.
Mr Lavrov made the warning during a call from US Secretary of State John Kerry, who in turn expressed concern about Russia's role in "inciting" trouble in eastern Ukraine, the Russian Foreign Ministry said in a statement.
The White House warned Russia against further military action in Ukraine after armed separatists seized government offices in the eastern city of Slaviansk today, saying the situation was reminiscent of what recently happened in Crimea.
Mr Lavrov said Ukraine was "demonstrating its inability to take responsibility for the fate of the country."He said that any use of force against Russian speakers in the east of Ukraine "would undermine the potential for cooperation."
US secretary of state John Kerry is heading back to the Middle East for talks with Israeli and Palestinian leaders as peace negotiations hit a critical make-or-break point.
The US state department said Mr Kerry will travel to Israel and the Palestinian territories amid a flurry of diplomatic activity by American mediators, in the hope of salvaging the troubled negotiations and getting them to extend the talks beyond a current late-April deadline.
The latest Ukraine crisis talks between US Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov in Paris have ended after four hours, a US official has said.
US Secretary of State John Kerry has said he hopes the current situation in Crimea will not have an impact on cooperation with Russia over the ongoing destruction of Syria's chemical weapons.
Mr Kerry also said the US is "convinced" that the Syria could move faster on the destruction programme than it is currently.
US Secretary of State John Kerry has told his Russian counterpart, Sergei Lavrov, that Russia must pull back its troops to their bases in Crimea, a US official has said.
Mr Kerry also reiterated that the White House regards today's referendum on the future of Crimea as illegal and the US government will not recognise the outcome.
Two of the EU's most senior officials, Jose Manuel Barroso and Herman van Rompuy, also released a joint statement calling the referendum "illegal and illegitimate".
John Kerry warned of "consequences" after his Russian counterpart made clear Moscow would respect the outcome of Crimea's referendum.Read the full story ›
US Secretary of State John Kerry has said Sergei Lavrov told him Vladimir Putin is not prepared to make any decision on Ukrainian's Crimea region until after Sunday's referendum.
Mr Kerry said the US and the EU are already clear on the referendum, describing it as "illegal under the Ukrainian constitution".
He said the international community will not recognise its outcome.
Mr Kerry said he also told Mr Lavrov, Russia's Foreign Minister, the US was concerned about the deployment of Russian troops in military exercises on the Ukraine border and the "increased anxiety" it had caused amid the current crisis.
The US Department of State and the Russian foreign ministry have posted pictures of John Kerry and Sergei Lavrov taking a stroll in the garden of the US Ambassador's residence in London:
David Cameron and John Kerry enjoyed a bit of a natter earlier today as they posed with William Hague for the cameras to mark the US Secretary of State's visit to Downing Street before his crisis-talks with Russia's Sergei Lavrov.
After the traditional handshake welcome, the Prime Minister described having a "lovely time" in Israel's boisterous parliament, the Knesset, a few days ago.
Mr Kerry responded that he looked forward to Mr Cameron's "download" on the key visit before joking with Mr Hague about them regularly crossing paths.
The group ended the staged sit-down by reiterating their commitment to taking action against Russia if a diplomatic solution to the Ukraine crisis cannot be found.