Iranian President Hassan Rouhani rejected negotiations with the Trump administration amid increasing tensions between Washington and Tehran.

“Today’s situation is not suitable for talks, and our choice is resistance only,” said Rouhani on Tuesday, according to the state news agency IRNA.

U.S. President Donald Trump has shown tough rhetoric, but also a willingness to sit down for talks with the regime.

“Iran will call us if and when they are ever ready,” he said on Monday, a day after tweeting, “If Iran wants to fight, that will be the official end of Iran. Never threaten the United States again!”

Since withdrawing last year from the 2015 Iran nuclear deal, the United States has increased pressure on the Islamic Republic by reimposing sanctions lifted under the deal.

This month, the United States enacting new sanctions and just deployedtwo warships with fighter jets, in addition to a Patriot missile battery, to the Gulf in response to Pentagon reports that Iran’s Islamic Revolutionary Guard Corps was planning an attack on U.S. forces or interests in the region.

The United States blamed Iran for being behind attacks against four commercial vessels off the Emirati coast, a U.S. official told ABC News on Tuesday.

Two oil tankers owned by Saudi Arabia and two others—one owned by the United Arab Emirates and another by Norway—were sabotaged last week.