The United States on Wednesday congratulated Shehbaz Sharif on becoming Pakistan's new prime minister following the ouster of his predecessor in a parliamentary no-confidence vote, with the top US diplomat reaffirming the "value" of the relationship between the two nations.

"Pakistan has been an important partner on wide-ranging mutual interests for nearly 75 years and we value our relationship," US Secretary of State Antony Blinken said in a statement. "The United States congratulates newly-elected Pakistani Prime Minister Shehbaz Sharif and we look forward to continuing our long-standing cooperation."

"The United States views a strong, prosperous, and democratic Pakistan as essential for the interests of both our countries," he added.

Blinken's statement came two days after Sharif took the oath of office following days of political turmoil leading to Khan's dismissal in the first no-confidence vote since 1947.

Analysts said they do not expect Washington to seek a significant broadening of ties, but to remain mostly focused on security cooperation, especially on counterterrorism and Afghanistan.

They also expected Sharif to be preoccupied with pressing domestic issues, especially trying to contain a serious economic crisis.

Ahead of the success of the no-confidence motion against former prime minister Imran Khan, he had accused the US of propagating a "regime change" in the country through the then leaders of the united opposition in the Parliament.

Citing the same allegations, Deputy Speaker Qasim Suri through a ruling dismissed the no-confidence motion against the former premier on April 3, proroguing the session of the National Assembly, while President Dr Arif Alvi dismissed the lower house of the Parliament on the advice of the ex-premier.

The Supreme Court then took suo moto notice of the political chaos and issued a landmark verdict in which it declared Suri's ruling null and void as it was against the Constitution, restored the National Assembly and ordered voting on the no-trust move on April 9.

The United States denied the allegations levelled by Khan, who did not provide any proof of the "threats" to security agencies, according to the reports.