Russia, Turkey and Iran were all due to compete in the United States before dropping out.

The Russian team withdrew after claiming the US Embassy in Moscow had refused to interview wrestlers from the country who had qualified for the competition - a prerequisite for obtaining entry visas.

Turkey withdrew for financial reasons and were originally replaced by Iran, who have won the last six editions of this event.

However, the powerhouse nation then dropped out, reportedly due to a scheduling dispute with UWW.

It means Mongolia and India have now come in to complete an eight-nation field at the Carver-Hawkeye Arena.

The host nation will contest Group A with Japan, India and Georgia with Azerbaijan, Cuba, Mongolia and Kazakhstan in Group B.

Both group winners will contest the gold medal while placing contests will also be held.

Notable matches to watch out for include Thomas Gilman of the US against Japan's Yuki Takahashi at 57 kilograms.

This is a repeat of last year's World Championship final won by the Japanese.

Olympic gold medalists Jordan Burroughs and Kyle Snyder will also be strong presences in the home squad.

Elsewhere, world bronze medalist Aslanbek Alborov, in his sixth World Cup appearance for Azerbaijan, will face world number one Luvsandorj Turtogtokh of Mongolia at 92kg.

At 65kg, three-time world champion and Olympic bronze medalist Haji Aliyev of Azerbaijan will face Cuba's Alejandro Enrique Valdes Tobier, contesting his third World Cup.

The competition runs over two days.