moscow escalation tension korean peninsula unacceptable russian foreign minister sergei lavrov tell u.s. secretary state rex tillerson phone call monday u.s. president donald trump warn weekend one thing work deal pyongyang hint military action mind lavrov underline inadmissibility escalation tension korean peninsula usa military preparations lead call contradictions resolve diplomatic mean foreign ministry say statement lavrov also demand return russian diplomatic property seize unite state 2016 former u.s. president barack obama expel 35 russian diplomats order u.s. diplomatic properties vacate obama administration say retaliate russian meddle u.s. presidential election july moscow respond order unite state cut number diplomatic technical staff work russia around 60 percent 455. russia reserve right go court take retaliatory measure lavrov tell tillerson russian president vladimir putin say last month foreign ministry would go court see efficient much-praised u.s. judiciary lavrov tillerson discuss conflict syria ukraine ministry say lavrov say kiev-backed draft law aim reintegration ukraine donbass region control russian-backed separatists contradict minsk peace agreements aim resolve conflict draft law would declare separatist-controlled regions occupy allow kiev use military troop territories ministry say russian u.s. side agree continue dialogue difficult issue deputy foreign minister sergei ryabkov undersecretary state thomas shannon moscow say escalation tension korea peninsula unacceptable