U.N. Secretary General Ban Ki-moon spoke to newly elected Ukrainian President Petro Poroshenko over the weekend and urged him to initiate a dialogue with Russian President Vladimir Putin, Ban's spokesman Stephane Dujarric said on Monday.

In the phone conversation with Poroshenko on Saturday, "the Secretary-General said while he fully understood the Ukrainian government's need to reassert full sovereignty over its territory, he underscored that this needs to be done through peaceful means," the UN spokesman said.