The self-declared new leader of Niger on Wednesday said the junta would not bow to pressure to reinstate ousted President Mohamed Bazoum, intensifying a standoff with the West African bloc, which has threatened to intervene after last week's coup.

The Economic Community of West African States (ECOWAS) has imposed sanctions on Niger and said it could authorize the use of force if the coup leaders do not restore Bazoum's presidency within a week from Sunday, July 30.

The bloc also sent a delegation to Niger on Wednesday to negotiate with the military officers who seized power, hoping to find a diplomatic solution before they have to decide whether or not to intervene.

"The military option is the very last option on the table, the last resort, but we have to prepare for the eventuality," said Abdel-Fatau Musah, ECOWAS Commissioner for Political Affairs, Peace and Security, on Wednesday as regional defense chiefs started a two-day meeting in the Nigerian capital Abuja.

In a televised address, Abdourahamane Tiani said the junta "rejects these sanctions altogether and refuses to give in to any threats, wherever they come from. We refuse any interference in the internal affairs of Niger."

Tiani, the former head of Bazoum's presidential guard, shut Bazoum in his palace last Wednesday and later declared himself head of state.

In a further sign of the mounting pressure on the junta, the World Bank on Wednesday suspended disbursements to Niger until further notice.

Foreigners evacuated

The United States ordered the evacuation of some staff and families from its embassy in Niger, the State Department said on Wednesday, even as the mission will remain open and senior leadership will continue working from there.

France and Italy have been evacuating European citizens from Niger amid growing fears of conflict. The first military planes carrying European nationals landed in Paris and Rome on Wednesday.

France said it had evacuated more than 350 French people so far.

France, the United States, Germany and Italy have troops in Niger on counterinsurgency and training missions, helping the army to fight groups linked to al Qaeda and Islamic State.

There has been no announcement of troops being withdrawn so far. Germany's defense minister said on Wednesday that there were no concerns about the safety of German soldiers.