Senegal's prime minister Ousmane Sonko raised the possibility of closing French military bases in the West African country on Thursday in a wide-ranging speech that also touched on the euro-backed CFA franc currency, oil and gas deals and LGBTQ rights.

Sonko, a firebrand politician who gained power when his hand-picked presidential candidate Bassirou Diomaye Faye won a decisive victory in March, is known for criticising perceived overreach by France in its former colony.

France has about 350 troops in Senegal.

"More than 60 years after our independence ... we must question the reasons why the French army for example still benefits from several military bases in our country and the impact of this presence on our national sovereignty and our strategic autonomy," Sonko said at a joint conference with the French left-wing politician Jean-Luc Melenchon in the capital Dakar.

"I reiterate here the desire of Senegal to have its own control, which is incompatible with the lasting presence of foreign military bases in Senegal ... Many countries have promised defence agreements, but this does not justify the fact that a third of the Dakar region is now occupied by foreign garrisons."

Neighbours Mali, Burkina Faso and Niger have pushed out French troops and turned to Russia for help fighting jihadist insurgencies on their territory.

They have also turned away from West African bloc ECOWAS - which condemned their coups - and formed their own alliance of Sahel states.

But Sonko had friendly words for them on Thursday.

"We will not let go of our brothers in the Sahel and we will do everything necessary to strengthen the ties," he said.

He also said Senegal, which shares the euro-pegged CFA franc currency with seven countries, would like a flexible currency pegged to at least two currencies to help absorb shocks and support export competitiveness.

During the election campaign, Faye had initially pledged to abandon the CFA franc but later backed off his promise.

Sonko reiterated promises to renegotiate oil and gas contracts in Senegal, where production is due to begin this year.

He also called on Western countries to show "restraint, respect, reciprocity and tolerance" on social matters including LGBTQ rights and gender equality.

He said homosexuality had always existed in Senegal, but the country had "managed" it and would continue to do so according to its socio-cultural realities.

"Senegal and many other African countries cannot accept any truth in legalising this phenomenon."