India's government has hit back at a senior White House official for commenting on the arrest of opposition party leader Arvind Kejriwal ahead of April's general election.

The Delhi chief minister is suspected of involvement in cases of graft relating to the city's liquor laws. Authorities arrested him last week.

Kejriwal leads the Aam Aadmi Party, and is a fierce critic of Prime Minister Narendra Modi.

Officials with the main opposition Congress party have also criticized the Modi administration in the run-up to the vote. They say tax authorities have frozen the party's bank accounts.

On Wednesday, US State Department spokesperson Matthew Miller said Washington encourages "fair, transparent, and timely legal processes for each of these issues."

In response, India's foreign ministry described Miller's remarks as "unwarranted."

The ministry also said, "Any such external imputation on our electoral and legal processes is completely unacceptable."

Opposition parties plan to hold a rally in New Delhi on Sunday to protest what they say is a crackdown right before the election.