"There are four to five principal requirements with respect to lifting the sanctions: release of hostages, release of all prisoners, is one; the withdrawal of the forces troops and equipment is another," Kerry said after a meeting with his Russian counterpart Sergei Lavrov in Paris.
"And at this point... Many of them are happening now, the troops are pulling back, the heavy equipment still has to be pulled back and the border is yet to be properly monitored and secured."
"We do not know who is losing out more in economic terms: Russia or the European Union," Lavrov said shortly before flying to Paris.
Russian President Vladimir Putin -- due to meet Poroshenko in Milan on Friday -- had boosted Lavrov's hand by calling back from the Ukrainian border 17,600 soldiers he had stationed there when Kiev's forces were making their most significant gains this summer.
The sanctions have cut Russia's access to Western money markets and forced its biggest state companies to appeal for massive rescues that will further limit the government's ability to meet its social commitments.