CAIRO, Feb. 19 (Xinhua) -- Naval forces of Iran and Russia held a joint drill on Thursday in the Gulf of Oman and the northern Indian Ocean, amid growing speculation about an impending U.S. military strike against Iran.

Special operation teams from Iran's army, the Islamic Revolution Guards Corps (IRGC), and Russia conducted an operation to liberate a hijacked ship during the exercise, according to a report on the Iranian army's website.

The drill involved Iran's Alvand destroyer, missile-launching warships, helicopters, landing craft, special operation teams, and combat speedboats, among others, the report said.

The exercise followed an IRGC drill in the Strait of Hormuz earlier this week, which included a temporary closure of the strategic waterway.

Meanwhile, U.S. President Donald Trump said Thursday that Iran has 10 to 15 days to reach a deal over its nuclear program, warning that otherwise "really bad things" will happen.

"I would think that would be enough time," Trump told reporters aboard Air Force One.

Last week, Trump ordered the deployment of the USS Gerald R. Ford, the world's largest aircraft carrier, to the Middle East, reinforcing the USS Abraham Lincoln and its accompanying guided-missile destroyers already in the region.

After a significant buildup of U.S. air and naval assets in the Middle East in recent days, the U.S. military is prepared to strike Iran "as early as this weekend," CNN reported Wednesday, citing sources familiar with the matter.

Axios, another U.S. news outlet, reported Tuesday that an advisor to Trump estimated a "90 percent chance" of strikes within weeks if nuclear negotiations with Iran fail.

Any U.S. operation could involve a large-scale, weeks-long campaign, potentially conducted jointly with Israel, targeting Iran's nuclear and missile programs and posing a major threat to Tehran's leadership, Axios reported.

On Thursday night, The Wall Street Journal, citing sources familiar with the matter, reported that Trump is weighing "an initial limited military strike" on Iran to compel it to meet his demands for a nuclear deal.

"The opening assault, which if authorized could come within days, would target a few military or government sites," it reported, adding that if Iran "still refused to comply with Trump's directive to end its nuclear enrichment," Washington will respond "with a broad campaign against regime facilities."

Iran and the United States concluded a second round of indirect nuclear talks in Geneva on Tuesday. Iran described the talks as more "constructive" than the first round, while U.S. officials acknowledged progress but said "there are still a lot of details to discuss."

White House Press Secretary Karoline Leavitt declined Wednesday to set a deadline for further talks, stating that while "there are many reasons and arguments for striking Iran," diplomacy remains Trump's "first option."

Given the tense situation, Polish Prime Minister Donald Tusk on Wednesday urged Polish citizens in Iran to leave immediately and advised against travel there.

Tusk said he did not intend to cause panic but warned that the risk of a "violent conflict" remains significant.