MOSCOW/LONDON, April 6 -- Opec+ has agreed in principle to raise its oil output quotas by 206,000 barrels per day for May, three sources with knowledge of the group's talks said ahead of its meeting later on Sunday, a rise that will largely exist on paper as its key members are unable to raise production due to the US-Israeli war with Iran. The war has effectively shut the Strait of Hormuz - the world's most important oil route - since the end of February and cut exports from Opec+ members Saudi Arabia, the UAE, Kuwait and Iraq, the only countries in the group which were able to significantly raise production even before the conflict began. Other group members such as Russia are unable to increase output due to Western sanctions and damage to infrastructure inflicted during the war with Ukraine. Inside the Gulf, damage to infrastructure from missile and drone attacks has also been severe. Several Gulf officials have said it would take months to resume normal operations and reach production targets even if the war stopped and Hormuz reopened immediately. Iran on Saturday said Iraq was exempt from any restrictions to transit the vital route, and shipping data on Sunday showed a tanker loaded with Iraqi crude passing through the strait. Still, it remains to be seen if more vessels will take the risk involved, a source close to the issue said. Sunday's Opec+ talks will include a gathering of ministers called the Joint Ministerial Monitoring Committee, which does not decide on output policy. After this, eight members of Opec+ hold separate talks having agreed in principle to raise output quotas by 206,000 bpd for May....