Prime Minister Narendra Modi on Sunday congratulated West Bengal Chief Minister Mamata Banerjee on her party's win in the assembly polls and assured the Centre's all possible support to the state government to fulfil people's aspirations and also to fight the COVID-19 pandemic.

In a series of tweets, Modi also offered congratulations to Kerala Chief Minister Pinarayi Vijayan, who heads the Left front in the state, and DMK supremo M K Stalin, who led the opposition alliance in Tamil Nadu, for their poll victories.

With the BJP retaining power in Assam, Modi said the state's people have again blessed the NDA's development agenda and the pro-people track record of its government.

"Congratulations to Mamata Didi for @AITCofficial's win in West Bengal. The Centre will continue to extend all possible support to the West Bengal Government to fulfil people's aspirations and also to overcome the COVID-19 pandemic," he tweeted.

In another tweet, Modi said, "I would like to congratulate Shri @vijayanpinarayi and the LDF for winning the Kerala Assembly elections. We will continue working together on a wide range of subjects and to ensure India mitigates the COVID-19 global pandemic."

In a tweet to Stalin, who is set to be the next Tamil Nadu Chief Minister, Modi said they will work together for enhancing national progress, fulfilling regional aspirations and defeating the COVID-19 pandemic.

The prime minister also expressed his gratitude to the people of West Bengal for boosting the BJP's presence.

"From a negligible presence earlier, BJP's presence has significantly increased. BJP will keep serving the people. I applaud each and every Karyakarta for their spirited effort in the polls," he said.

"Gratitude to the people of Kerala who supported our party in these elections, he said in another tweet and lauded party workers for their efforts," he tweeted.

In another post, he said, "I would like to thank the people of Tamil Nadu who supported NDA. I assure the people of Tamil Nadu that we will keep working towards the state's welfare and to further popularise the glorious Tamil culture. I applaud our Karyakartas for their hard work."

The prime minister also thanks voters in Karnataka, Maharashtra, Gujarat, Rajasthan and Uttarakhand for backing the BJP in various by-polls.

"Our party will keep working for people's welfare. Gratitude to the BJP Karyakartas for their untiring determination," he said.