Here is what we know about the US response and administration thinking.

- How has the US reacted to the attacks? -

It took only hours for Washington to directly accuse Tehran of being "responsible" for the attacks Thursday against two oil tankers.

The incident had Iran "written all over it," Trump said Friday, rejecting Tehran's denial of any such role. The president pointed to a video that purports to show a patrol boat of Iran's Revolutionary Guards pulling alongside one of the tankers to remove an unexploded limpet mine from the ship's hull.

But the US condemnations were not followed by threats of any immediate retaliation. That represented a degree of restraint by an administration that has been steadily tightening economic and diplomatic sanctions against Iran, and which last month stepped up its "maximum pressure" campaign with new deployments of ships, bombers and troops to the region.

- War of words, or just plain war? -

"The situation between the US and Iran is becoming increasingly dangerous," tweeted Colin Kahl, a former Obama administration national security advisor now at Stanford University in California.

Both sides could "easily... slide into a war they claim they want to avoid," he said.

Between the continuing war of words and the recent escalation, numerous observers and US allies fear an incident could degenerate into open conflict.

But Aaron David Miller, a former negotiator in both Democratic and Republican administrations, does not see the recent attacks as "sufficient for a casus belli."

"If, in the wake of this incident, the Trump administration chose to strike Iranian vessels directly, or the Iranian mainland, or Iranian forces in Iraq and Syria, or in Yemen, you have zero support," said Miller, now a Middle East expert at the Wilson Center think tank.

- A 'focus on diplomacy' -

Trump, for his part, has made it abundantly clear: He does not want to embroil the country's military in another costly and "endless" war like those in Afghanistan and Iraq.

If acting US defense secretary Patrick Shanahan has expressed a determination to "defend our forces and our interests around the world," he has also reiterated that Washington "does not seek conflict."

Pentagon spokesmen have stressed that neither American interests nor personnel have yet been attacked -- making it an issue affecting global maritime traffic that should be settled at the international level.

"We have an international situation there in the Middle East, it's not a US situation," Shanahan told reporters on Friday, saying the administration was united in seeking an "international consensus to this international problem."

But it is no secret that the president's national security advisor, John Bolton, has taken far more aggressive positions. Secretary of State Mike Pompeo is also considered a hawk on Iran, even if he has attempted to hew to Trump's more restrained line.

- What does Trump want? -

Beyond the question of how to respond to the recent attacks, a much larger question remains: What exactly is the concrete objective of the American pressure strategy against Iran?

Last year Trump pulled the US out of the multinational 2015 accord that was designed to prevent Tehran from producing nuclear weapons.

He was harshly critical of the pact, negotiated during the Obama presidency, and said he wanted to compel the Islamic Republic to accept much more stringent restrictions on its nuclear program and to cease any "destabilizing" behavior in the Middle East.

In recent weeks, even as his teams were cranking up the economic, diplomatic and military pressure on Iran, the president has issued repeated calls for direct dialogue with Iranian leaders.

But with supreme Iranian leader Ayatollah Ali Khamenei flatly refusing to talk, Trump seems uncertain how to proceed.

"I personally feel that it is too soon to even think about making a deal," the president said Thursday on Twitter, before again on Friday repeating his invitation:

"We want to get them back to the table if they want to go back," he said on the "Fox & Friends" program. "I'm ready when they are. Whenever they're ready, I'm OK."

"The real problem is that there is no endgame in the administration's strategy," said Miller. "Regime collapse or change is fantastical right now."

Miller sees a disturbing lack of clarity in the administration's approach.

"What's the purpose of the sanctions?" the former diplomat asked. "Is it to destroy the Iranian economy? Or is it a serious effort to drag the Iranians into the negotiations and produce a better outcome than what Obama got?"

"I don't believe that this administration is prepared to (make) the kind of concessions that the Iranians would demand in a serious negotiation."