Arresting Imran Khan will only deepen the crisis in Pakistan, says former US envoy to Afghanistan and Pakistan Zalmay Khalilzad.

In a series of tweets on Tuesday, Khalilzad offered Islamabad advice on how to deal with the political, economic and security crises being faced by the country.

His advice came as a heavy police force led by Islamabad's chief cop reached Zaman Park after Islamabad police failed to arrest Pakistan Tehreek-e-Insaf (PTI) Chairman Imran Khan amid fierce clashes between PTI workers and the anti-riot force in and around the party chief’s residence that left dozens of activists and police personnel injured.

The former US special envoy for Pakistan and Afghanistan opined that "despite great potential", Pakistan is underperforming and "falling far behind its archrival, India".

"It is time for serious soul-searching, bold thinking, and strategizing," he wrote, sharing his thoughts on how to tackle the problems.

Secondly, he suggested that this time be used for the main political parties to "confront" what has gone wrong and propose a specific plan to "rescue and put the country on a path to stability, security and prosperity".

"Whichever party wins the election will have a mandate from the people on what must be done,” he said.