Poroshenko calls for sanctions on Russia to remain

"Anything less would be a compromise at the cost of values and justice," Poroshenko added. Poroshenko also said that some 10,000 people, including more than 2,700 Ukrainian army troops, had been killed in fighting between pro-Russian separatists and Ukrainian armed forces since April 2014. He said nearly 1.8 million people had been forced to leave their homes in the eastern regions of Donetsk and Luhansk over the same time period.  Poroshenko also expressed surprise at the international community's reluctance to provide Ukraine with lethal military assistance.  Poroshenko is in Washington to take part in the Nuclear Security Summit being hosted by U.S. President Barack Obama.  The Ukrainian leader is scheduled to meet with U.S. Vice President Joe Biden later on March 31.