Officials from Russia, Ukraine, Turkey and the United Nations are likely to meet this week to discuss resuming grain exports from Ukraine to the Black Sea, Turkish Defense Minister Hulusi Akar said on Monday, Reuters reported.

Akar said last week that Russia, Ukraine, Turkey and the United Nations would sign an agreement on a grain export corridor this week, but U.N. chief Antonio Guterres warned that there was still "a long way to go" before peace talks to end the war could begin.

Akar said Monday that agreement had been reached on a "plan, general principles" for an export corridor, and added that a meeting of all sides to discuss details was likely this week.

He said technical issues such as establishing a monitoring center in Istanbul, determining safe routes and checkpoints at the exits and entrances to the ports are on the agenda.