India has witnessed its third and final presidential election in two decades, and the polls are expected to be conducted by mid-November.
In the lead-up to the election, the Modi government has been accused of corruption, but on Thursday, a fresh round of allegations emerged against its prime minister and his party, the Congress.
Mr Modi is under a major investigation by the Central Bureau of Investigation (CBI) over alleged payments to his aides for work related to the 2009 general elections.
In a tweet on Thursday morning, Mr Modi said, “We are not the victims of a conspiracy, but of a political witch hunt.”
The tweets followed a series of tweets from Mr Modi, in which he accused the CBI of interfering in elections, and questioned the validity of the results of the polls.
“What are you doing?”
Mr Modi tweeted.
“Are you trying to take away our right to vote?
Do you have the guts to investigate what the people of our country are voting for?”
Mr Modi’s tweet followed another tweet from Mr Trump, who accused the election process of being rigged.
“The election results of India will be released soon, but what is the real story?
What are you hiding?
Who is the culprits?” he tweeted.”
India’s future depends on it,” Mr Trump added.
Mr Trump is the third person to publicly criticise the election results, following the former US president Barack Obama and US senator Bernie Sanders.
In another tweet, Mr Trump said he was confident that the polls would be “fair”.
“The world looks on and they will say, ‘Yes, we have an honest election’, but what about the election result?” he said.
“Will they vote for you?”
“I will vote for my friends and the people who voted for me,” he added.
A series of attacks have been made on the elections on social media, with some commentators comparing them to the 2008 presidential elections.
A recent survey by the US polling firm Public Policy Polling (PPP) found that voters were more likely to vote for Mr Trump and his supporters if they believed he would “do something good” than if they thought he would be a “fraud” or “loser”.
The BJP, which has governed India for almost four decades, has long denied allegations of corruption.
