Ukrainian President Petro Poroshenko on Tuesday launched an uphill battle for re-election, five years on from a bloody uprising that brought him to power on a promise to tackle corruption.

Ukrainian President Petro Poroshenko on Wednesday announced the end of a martial law in the country's border regions, which was introduced last month after Russia's seizure of three of Kiev's navy vessels in the Sea of Azov. "Today, right now, at 2:00 pm (1200 GMT) the martial law ends. This is my principal decision," Poroshenko…

Russian President Vladimir Putin said Saturday he briefed his US counterpart Donald Trump on the Ukraine crisis as he came under pressure over Moscow's robust foreign policy at the G20 summit in Argentina.

US President Donald Trump headed to Argentina Thursday for a fractious weekend of G20 summitry, cancelling planned talks with Russia's leader...

Ukraine's president signed an act imposing martial law in border regions on Wednesday as mounting tensions over Russia's seizure of Ukrainian ships saw US President Donald Trump threaten to cancel talks with Vladimir Putin.

NATO will hold an emergency meeting with Ukrainian officials at alliance headquarters in Brussels on Monday over the naval standoff with Russia off the coast of Crimea.

Ukrainian President Petro Poroshenko on Saturday condemned the influential Russian Orthodox Church, which counts millions of believers, as a threat to national security.

Ukraine on Friday charged a prisoner swap negotiator with plotting to assassinate President Petro Poroshenko and other top officials leading the four-year campaign against Russian-backed eastern insurgents.

"Above all, this decision is very, very saddening," Erdogan said in his first reaction to the decision, at a news conference with Ukrainian counterpart Petro Poroshenko in Kiev.

The White House on Monday alleged that Democrats colluded with Ukraine during the 2016 election, turning the tables on its accusers amid an all-engulfing scandal over Trump's contacts with Russia.

US Vice President Mike Pence will meet Petro Poroshenko in Washington on Tuesday, the White House said, but there was no word on whether the Ukrainian president will be hosted by his opposite number Donald Trump.

Ukrainians were on Sunday celebrating the first day of visa-free access to the European Union, with hundreds crossing the border as President Petro Poroshenko proclaimed a dramatic "breakaway" from Moscow.