An emboldened U.S. President Donald Trump has hinted that he has other countries in his sights after toppling Venezuela's Nicolas Maduro, leaving the world asking: where's next?

Key Ukrainian allies were to huddle with top U.S. envoys in Paris on Tuesday to discuss security guarantees, as they press ahead on U.S.-brokered plans to end the war with Russia.

Widening protests in Iran sparked by the Islamic Republic's ailing economy are putting new pressure on its theocracy.

Tehran is still reeling from a 12-day war launched by Israel in June that saw the United States bomb nuclear sites in Iran. Economic pressure, which has intensified since September when the United Nations reimposed sanctions on the country over its atomic program, has put Iran's rial currency into a free fall, now trading at some 1.4 million to $1.

President Donald Trump's military intervention in Venezuela will pose a fresh test of his ability to hold together a restive Republican coalition during a challenging election year that could be defined by domestic concerns like health care and affordability.

While most Republicans lined up behind the president in the immediate aftermath of the stunning U.S. mission to capture Venezuelan leader Nicolás Maduro and bring him to New York to face criminal charges, there were signs of unease across the spectrum within the party. In particular, Trump's comments about the U.S. positioning itself to "run" Venezuela have raised concerns that he is abandoning the "America First" philosophy that has long distinguished him from more traditional Republicans and helped fuel his political rise.

Deposed Venezuelan President Nicolás Maduro is set to make his first appearance Monday in an American courtroom on the narco-terrorism charges the Trump administration used to justify capturing him and bringing him to New York.

Maduro and his wife are expected to appear at noon before a judge for a brief, but required, legal proceeding that will likely kick off a prolonged legal fight over whether he can be put on trial in the U.S.

A day after the audacious U.S. military operation in Venezuela, President Donald Trump on Sunday renewed his calls for an American takeover of the Danish territory of Greenland for the sake of U.S. security interests and threatened military action on Colombia for facilitating the global sale of cocaine, while his top diplomat declared the communist government in Cuba is "in a lot of trouble."

The comments from Trump and Secretary of State Marco Rubio after the ouster of Venezuela's Nicolás Maduro underscore that the U.S. administration is serious about taking a more expansive role in the Western Hemisphere.

Venezuela's interim president Delcy Rodriguez has called for a "balanced and respectful" relationship with the United States, a day after American forces attacked Caracas and captured leftist leader Nicolas Maduro.

"We consider it a priority to move toward a balanced and respectful relationship between the U.S. and Venezuela," Rodriguez, Maduro's vice president, wrote on Telegram.

Russia's overnight strikes on Kyiv province killed two people, Ukrainian authorities said Monday after a countrywide air alert was issued.

One person was killed in the capital, according to Tymur Tkachenko, the head of the city's military administration.

Iran accused Israel on Monday of trying to undermine its national unity after Israeli Prime Minister Benjamin Netanyahu expressed support for protests in the Islamic republic.

"The Zionist regime (Israel) is determined to exploit the slightest opportunity to sow division and undermine our national unity, and we must remain vigilant," foreign ministry spokesman Esmail Baqaei said at a weekly press conference, before accusing Israeli and US leaders of "incitement to violence".

Venezuela's president Nicolas Maduro was in a New York jail on Sunday after a shock U.S. snatch-and-grab raid to remove him from power and assert Washington's control over the oil-rich South American nation.