Denmark's foreign minister said Thursday he was "more optimistic" after technical talks kicked off with the United States over Greenland.

"We have had the very first meeting at senior official level in Washington yesterday regarding the Greenlandic issue," Lars Lokke Rasmussen told journalists at an EU meeting in Brussels.

Turkey will offer to help resolve tensions between Washington and Tehran when Iran's top diplomat visits, a foreign ministry source said Thursday a day ahead of the visit.

"Turkey is ready to contribute to resolving the current tensions through dialogue," Turkish Foreign Minister Hakan Fidan was to tell his counterpart Abbas Araghchi when the pair meet on Friday, the source said.

Iran's foreign minister warned Wednesday its forces would respond immediately and forcefully to any U.S. military operation after President Donald Trump declared time was running out to avoid one, but did not rule out a new deal on Tehran's nuclear program.

The Islamic republic's top diplomat Abbas Araghchi warned its forces have their "fingers on the trigger" to "powerfully respond" to any U.S. strikes, but also used language strikingly similar to Trump's to describe a possible agreement to defuse the stand-off through a new nuclear deal.

The European Union on Thursday announced sanctions on 15 Iranian officials, including top commanders and officials of the paramilitary Revolutionary Guard, over Tehran's deadly crackdown on nationwide protests.

Six Iranian organizations, including bodies responsible for monitoring online content in Iran, were also included in the sanctions list.

U.S. President Donald Trump on Wednesday called on Iran to "come to the table and negotiate a fair and equitable deal," warning Tehran of a "far worse" attack if it does not "make a deal."

“A massive Armada is heading to Iran. It is moving quickly, with great power, enthusiasm, and purpose. It is a larger fleet, headed by the great Aircraft Carrier Abraham Lincoln, than that sent to Venezuela. Like with Venezuela, it is, ready, willing, and able to rapidly fulfill its mission, with speed and violence, if necessary,” Trump warned.

Iranian officials reached out to the wider Middle East on Wednesday over the threat of a possible U.S. military strike on the country, a month since the start of protests in Iran that soon spread nationwide and sparked a bloody crackdown.

Two nations, Saudi Arabia and the United Arab Emirates, have signaled they won't allow their airspace to be used for any attack. But America has moved the USS Abraham Lincoln and several guided missile destroyers into the region, which can be used to launch attacks from the sea.

There can be no negotiations between Washington and Tehran if the United States makes threats against the Islamic republic, the Iranian foreign minister said Wednesday, with President Donald Trump refusing to rule out military action over Iran's crackdown on protesters.

"Conducting diplomacy through military threat cannot be effective or useful. If they want negotiations to take shape, they must certainly set aside threats, excessive demands and raising illogical issues," said Abbas Araghchi after the U.S. deployed an aircraft carrier in the region.

Secretary of State Marco Rubio plans on Wednesday to warn that the Trump administration is ready to take new military action against Venezuela if the country's interim leadership strays from U.S. expectations.

In prepared testimony for a hearing before the Senate Foreign Relations Committee, Rubio says the U.S. is not at war with Venezuela and that its interim leaders are cooperating, but he notes that the Trump administration would not rule out using additional force if needed following a raid to capture former President Nicolás Maduro early this month.

Russian strikes across Ukraine killed three people and wounded several more, authorities said on Wednesday.

The fresh strikes came hours after Russian attacks on Tuesday night had killed at least 12 people across Ukraine, including five passengers in a train targeted by a drone attack, according to Ukrainian authorities.

Europe must step up efforts on defense and play a bigger role in NATO as U.S. President Donald Trump has "shaken the transatlantic relationship to its foundation", EU top diplomat Kaja Kallas said Wednesday.

"Let me be clear: we want strong transatlantic ties. The US will remain Europe's partner and ally. But Europe needs to adapt to the new realities. Europe is no longer Washington's primary centre of gravity," Kallas told a defence conference in Brussels.