Source: Sharecast
As of 1230 BST, Dow Jones futures were up 0.69%, while S&P 500 and Nasdaq-100 futures had the indices opening 0.79% and 1.00% firmer, respectively.
The Dow closed 374.96 points higher on Monday as investors shrugged off concerns about America's bombing of Iran.
The Middle East conflict was in focus again on Tuesday after Israel, which launched strikes against Iran 12 days ago, said it had achieved its primary objectives, removing "dual immediate existential threat from itself" both in the nuclear and ballistic missile fields.
However, air raid sirens were reported to have sounded in northern Israel just hours after Donald Trump claimed a ceasefire agreement had been struck. Media reports indicated that two missiles had been intercepted, and although Iran denied launching them, Israeli defence minister Israel Katz ordered immediate retaliation on Tehran.
"I have instructed the IDF to respond forcefully to Iran's violation of the ceasefire with powerful strikes against regime targets in the heart of Tehran," said Katz.
Iran also fired missiles at a US airbase in Qatar in what has generally been seen as a symbolic reprisal for American attacks on nuclear infrastructure.
Tuesday's other main focus will be testimony from Federal Reserve chairman Jerome Powell before the House Financial Services Committee at 1500 BST, where he will present the central bank's monetary policy report. Powell will then testify before the Senate Banking Committee on Wednesday.
On the macro front, the Chicago Federal Reserve's May national activity index will be published at 1330 BST, while April's housing price index was slated for release at 1400 BST, and June consumer confidence figures and Richmond Fed manufacturing index will follow at 1500 BST.
No major corporate earnings were slated for release on Tuesday.
Reporting by Iain Gilbert at Sharecast.com