The Black Sea grain corridor ground to a halt on Tuesday after no ship inspections were conducted under the safe-passage deal that allows Ukraine to export its crops from three key ports, although activity is now expected to resume on Wednesday.

The Joint Coordination Centre in Istanbul didn’t conduct inspections as the parties involved “needed more time to reach an agreement on operational priorities,” the United Nations said in a statement. Inspections are expected to restart tomorrow after “intensive discussions,” it said.

The JCC hosts teams from Ukraine, Russia, Turkey and the United Nations that mutually check all ships headed to and from the three ports covered by the Black Sea grain agreement.

The deal has significantly boosted crop flows from the war-torn country since it was agreed in July, but the speed of inspections has been a bottleneck, with only a handful of ships usually cleared daily.

“We urge all involved to meet their responsibilities to ensure that vessels continue to move smoothly and safely in the interest of global food security,” said Stephane Dujarric, spokesman for the UN secretary-general.

Ukraine also recently faced a backlash from eastern European Union nations over grain shipments there. It pledged to suspend exports of key crops to Poland until next season, while cargoes bound for third countries are still permitted.

The Black Sea pact was extended in mid-March. Russia has threatened to withdraw next month unless progress is made to remove obstacles for its own exports, although it remains the world’s top wheat shipper.

Lineups posted by the United Nations show two inbound and four outbound vessels were cleared Monday. No cleared ships were listed on Tuesday.