The instructions to the military are to have been approved during conversations with the president's highest advisor in the White House's so-called situation room on Tuesday.
Trump has urged Iran to surrender "unconditionally" and on Wednesday Trump said he "maybe" will draw the USA into the war.
I have ideas about what I will do, but I have not made any final decision. I like to make the final decision a second before it's time, said Trump to reporters.
Nuclear facility possible target
Iran's well-protected enrichment facility Fordo southwest of Tehran is a possible American target. There, uranium is enriched deep inside a mountain, which makes the facility difficult for Israel to attack.
Only American bunker-busting bombs are believed to have the capability to take out the facility, according to military experts.
We are the only ones who have the capacity to do it, but that does not mean I will do it, said Trump about the possibility of destroying the facility.
Promises retaliation
Iran's supreme leader ayatollah Ali Khamenei said in a public appearance on Wednesday that Israel has made a "huge mistake" and at the same time warned the USA of retaliation if Trump chooses to enter the war.
Americans should know that any American military intervention without a doubt will be followed by damage that cannot be repaired, said Khamenei, who also promised to punish Israel.
The USA has during the spring placed strategic bomber planes in the Indian Ocean and in recent days further military reinforcements have been sent to the Middle East. A third American destroyer has recently arrived in the eastern Mediterranean and a second aircraft carrier is on its way to the Arabian Sea, writes Wall Street Journal.
