Iran has threatened to block nuclear inspections next month, and further increased production of fuel that could be enriched for use in bombs. It has seized an American ally’s cargo ship. And it has incarcerated yet another American citizen on spying charges. These are just some of the steps Iran has taken in recent weeks in what is seen as part of an increasingly impatient strategy to pressure President Biden, who has said he wants to reverse many actions taken by his predecessor, Donald J. Trump.

Those reversals include returning to the 2015 Iranian nuclear accord, abandoned by Mr. Trump, which had severely constrained Iran’s nuclear program. Iran’s adversaries have long seen that program as a path toward the country building nuclear weapons, but Tehran insists that it has always been intended only for peaceful purposes. Mr. Trump slapped many tough economic sanctions on Iran in what he called a “maximum pressure” strategy to force the Iranians to renegotiate the accord. But Iran refused to renegotiate and instead ramped up its nuclear activity after the U.S. withdrawal from the deal, while also pursuing its missile program and regional policies opposed by the United States.

The Iranian parliament passed legislation that required the government to abandon its obligations under the nuclear deal in a series of defined steps. “Iran is shifting phases from waiting and patience to aggression and action. It is time and the enemy can see the signs very clearly,” a conservative analyst in Iran, Mehdi Mohammadi, said in a Twitter post early this month.

But Mr. Biden has shown no particular urgency in re-engaging with Iran in the week since he was inaugurated, preoccupied with numerous other crises in a spillover from the Trump years, most notably the uncontrolled Covid-19 pandemic and America’s own economic travails. Moreover, the pushback from Republicans, the pro-Israel lobby and vocal opposition groups highlighting Iran’s human rights violations make a return to the nuclear agreement with a stroke of the presidential pen politically tricky.

Even so, Iranian leaders’ irritation at the lack of action has escalated in recent days, given Mr. Biden’s flurry of executive orders on other matters. From President Hassan Rouhani and his subordinates, a chorus has been urging — through interviews, social media and public comments — that Mr. Biden move quickly to restore the accord without imposing any preconditions on Iran. In turn, Iran has pledged that it, too, would return to honoring its commitments to cap enrichment and allow inspectors access.

“If they issue an order, Iran too will issue an order, not more. If they return to their commitments, we will also return to our commitments,” said Mr. Rouhani at a televised cabinet meeting on the day of Mr. Biden’s inauguration.