Iran is preparing to send a flotilla of warships to the Atlantic Ocean following the announcement of a massive $500 million investment in war spending, according to Iranian leaders, who say the military moves are in response to recent efforts by the United States to impose a package of new economic sanctions on Tehran.

The military investment and buildup comes following weeks of tense interactions between Iran and the United States in regional waters, where Iranian military ships have carried out a series of dangerous maneuvers near U.S. vessels. The interactions have roiled U.S. military leaders and prompted tough talk from the Trump administration, which is currently examining potential ways to leave the landmark nuclear deal.

Iran's increasingly hostile behavior also follows a little-noticed United Nations report disclosing that Iran has repeatedly violated international accords banning ballistic missile work. Lawmakers in the U.S. Congress and some policy experts also believe that Iran has been violating some provisions in the nuclear agreement governing nuclear-related materials.

With tensions over sanctions and Iran's compliance with the nuclear agreement growing, Iranian parliamentary members voted to increase war spending by more than $500 million. This is at least the second recent cash influx to Iran's military since the landmark nuclear deal that unfroze billions in Iranian assets and saw the United States awarding Tehran millions in cash.

Iranian lawmakers reportedly shouted "death to America" as they passed the measure, which boosts spending to Iran's contested missile programs by around $260 million.

The bill also imposes sanctions on U.S. military officials in the region. Additionally, Iranian officials are moving to set up courts to prosecute the United States for the recent sanctions, which Iran claims are in violation of the nuclear deal.

Meanwhile, following several aggressive encounters with U.S. military vessels in the Persian Gulf, Iranian military leaders announced that they would be leading a flotilla of warships into the Atlantic Ocean.

"No military official in the world thought that we can go round Africa to the Atlantic Ocean through the Suez Canal but we did it as we had declared that we would go to the Atlantic and its Western waters," Iranian Navy Commander Rear Admiral Habibollah Sayyari was quoted as saying over the weekend.

"We moved into the Atlantic and will go to its Western waters in the near future," Sayyari said.

U.S. military officials reported Monday yet another "unsafe" encounter with an Iranian drone that was shadowing a U.S. carrier in the Persian Gulf region and reportedly came close enough to an American F-18 jet to risk the pilot's life.

As with other similar encounters during the past months, the Iranian craft did not respond to repeated radio calls by the United States. While the drone is said to have been unarmed, it is capable of carrying missiles.

Iranian leaders have been adamant that the country will not halt its work on ballistic missile technology, which could be used to carry nuclear weapons.

The United States has issued several new packages of sanctions as a result of this behavior, but U.N. members have yet to address the issue, despite recent reporting that found Iran is violating international accords barring such behavior.

"Little-noticed biannual reporting by the UN Secretary General alleges that Iran is repeatedly violating these non-nuclear provisions," Iran Watch, a nuclear watchdog group, reported on Monday.

"Thus far, the United States has responded to such violations with sanctions and designations of Iranian and foreign entities supporting Tehran's ballistic missile development," the organization found. "However, the U.N. and its member states have not responded. More must be done to investigate allegations of noncompliance and to punish violations of the resolution."

Rep. Sean Duffy (R., Wis.), a proponent of a more forceful policy on Iranian intransigence in the region, told the Free Beacon that the Trump administration must make it a priority to address Tehran's increasingly bold military activity.

"Iran was emboldened to flex its military muscle after eight years of President Obama’s passivity and his delivery of cold, hard cash to the regime, but they should make no mistake: President Trump was elected to put a stop to rogue regimes pushing America around, and the American people know he will address the world’s lead sponsor of terrorism with resolve," Duffy told the Free Beacon.

Michael Rubin, a former Pentagon adviser and expert on rogue regimes, said that Iran's recent behavior shows the regime has not moderated since the nuclear deal was implemented. The Obama administration sold the deal in part on promises that it could help bring Tehran into the community of nations.

"Every time the Islamic Republic has cash, it chooses guns over butter," Rubin told the Washington Free Beacon. "What the [nuclear deal] and subsequent hostage ransom did was fill Iran's coffers, and now we see the result of that."

"What [former President Barack] Obama and [former Secretary of State John] Kerry essentially did was gamble that if they funded a mad scientist's lab, the scientist would rather make unicorns rather than nukes," Rubin said. "News flash for the echo chamber: Iranian reformist are just hardliners who smile more. Neither their basic philosophy nor their commitment to terrorism have changed."

Update 6:52 p.m.: This post has been updated to reflect comment from Rep. Duffy.