GAZA (Reuters) - A planned trip to Moscow next week by the leader of Hamas has been canceled, Palestinian officials said on Thursday amid new friction between the Islamist group that controls Gaza and the Palestinian Authority, based in the West Bank.

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The Jan. 15 meeting between Hamas chief Ismail Haniyeh and Russian Foreign Minister Sergei Lavrov was called off due to Lavrov’s busy schedule, Moussa Abu Marzouk, a senior Hamas official, tweeted. No new date was announced.

The cancellation was first reported by Russia’s Interfax news agency, which cited information from the Palestinian Authority’s ambassador.

A long-running dispute between Hamas and the Palestinian Authority over power-sharing worsened this week when the PA pulled its personnel from Gaza’s Rafah border crossing with Egypt. They were replaced by Hamas employees.

Egypt responded by blocking the entry of travelers from Gaza through Rafah, the Palestinian territory’s main exit to the world.

Israel maintains tight restrictions on its border crossings with Gaza, citing security concerns.

Haniyeh had been due to travel to Russia via Egypt, but it was unclear whether Rafah’s closure would have prevented him from making the visit.

In the past, Egypt has allowed Hamas leaders in even when Rafah has been closed to the public. Battling an Islamic State insurgency in the Sinai peninsula that borders Gaza, Egypt has frequently curtailed passage through Rafah.

Two senior Egyptian security officials met Hamas representatives in Gaza on Thursday to discuss the faltering unity efforts as well as tensions along the border with Israel, Palestinian sources said.

Hamas, which seized the Gaza Strip in a brief Palestinian civil war in 2007, and the PA have failed repeatedly to implement an Egyptian-mediated reconciliation deal.