The nuclear powered aircraft carrier USAbraham Lincoln at Newport News Shipbuilding in Newport News, Va. April 27, 2016. (Photo: AP)

The US is sending an aircraft carrier group to the Middle East ahead of schedule and warning that Iran and its proxy forces are showing “troubling and escalatory” indications of a possible attack on American forces in the region.

Exactly what prompted the action was unclear, but it marked a further step in sharply rising tensions between the Trump administration and the Islamic Republic.

National Security Adviser John Bolton said Sunday night the US was deploying the USAbraham Lincoln Carrier Strike Group and a bomber task force to the Middle East, intending to send a message that “unrelenting force” will meet any attack on American forces or allies.

“The United States is not seeking war with the Iranian regime, but we are fully prepared to respond to any attack, whether by proxy, the Islamic Revolutionary Guard Corps or regular Iranian forces,” he said.

Neither Bolton nor other officials would provide any details about the supposed threat, which comes as the Trump administration wages a campaign of intensifying pressure against Iran and nearly a year after it withdrew from an Obama-era nuclear deal with Tehran.

In Iran, the semi-official ISNA news agency on Monday quoted an anonymous official as saying that Iranian President Hassan Rouhani planned a broadcast address Wednesday and might discuss “counteractions” Tehran will take over America’s withdrawal from the international nuclear deal.

The agreement limited Iran’s enrichment of uranium amid Western concerns that Tehran’s program could allow it to build nuclear weapons. Iran insists its program is for peaceful purposes.

With its pressure campaign, the US administration is trying to get Iran to halt activities such as supporting militant activities that destabilize the Middle East and threaten US allies, including Israel, Secretary of State Mike Pompeo said.

“Our objective is to get the Islamic Republic of Iran to behave like a normal nation,” Pompeo told reporters during a visit to Finland. “When they do that, we will welcome them back.”

The order to the carrier group would get the Abraham Lincoln into the Middle East about two weeks earlier than initially planned following exercises in the Mediterranean region, according to the defense official, who wasn’t authorized to speak publicly so spoke on the condition of anonymity.

For years, the US maintained a carrier presence in the Persian Gulf and Middle East region. During the height of the wars in Iraq and Afghanistan, there were two carriers in the area, but that was reduced to one.

Last year the administration decided to end the continuous carrier presence, and send a strike group only intermittently into the region. The US Navy currently has no aircraft carrier in the Persian Gulf.

Bolton said the US wants to send a message that “unrelenting force” will meet any attack on US interests or those of America’s allies.

Along with the Lincoln, Bolton mentioned “a bomber task force,” which suggested the Pentagon is deploying land-based bomber aircraft somewhere in the region, perhaps on the Arabian Peninsula.

Pompeo said the actions undertaken by the US have been in the works for a while.

“It is absolutely the case that we have seen escalatory actions from the Iranians and it is equally the case that we will hold the Iranians accountable for attacks on American interests,” Pompeo said. “If these actions take place, if they do by some third-party proxy, a militia group, Hezbollah, we will hold the Iranian leadership directly accountable for that.”

Asked about “escalatory actions,” Pompeo replied, “I don’t want to talk about what underlays it, but make no mistake, we have good reason to want to communicate clearly about how the Iranians should understand how we will respond to actions they may take.”

Asked if the Iranian action was related to the deadly events in Gaza and Israel — militants fired rockets into Israel on Sunday and Israel responded with airstrikes — Pompeo said, “It is separate from that.”

The Trump administration has been intensifying its pressure campaign against Iran.

Last month, President Donald Trump announced the US would no longer exempt any countries from US sanctions if they continue to buy Iranian oil, a decision that primarily affects the five remaining major importers: China and India and US treaty allies Japan, South Korea and Turkey.

The US also recently designated Iran’s Revolutionary Guard as a terrorist group, the first ever for an entire division of another government.

Trump withdrew from the Obama administration’s landmark nuclear deal with Iran in May 2018 and, in the months that followed, reimposed punishing sanctions including those targeting Iran’s oil, shipping and banking sectors.