President Donald Trump meets with immigration crime victims at the White House in Washington, U.S., June 28, 2017. REUTERS/Yuri Gripas President Donald Trump suggested on Sunday that he will not pursue a joint cybersecurity task force with Russia, throwing cold water on speculation that sprung from comments he made on Twitter earlier in the day.

"The fact that President Putin and I discussed a Cyber Security unit doesn't mean I think it can happen. It can't-but a ceasefire can,& did!" Trump said in a tweet Sunday evening.

The tweet seemed to be an attempt to quell criticism of Trump's highly publicized meeting with Russian President Vladimir Putin.

After the meeting, conflicting reports emerged over how strongly Trump pressed Putin about Russian interference in the US election and whether Trump accepted Putin's denials of involvement. Trump then raised eyebrows by revealing on Twitter earlier Sunday that they had discussed forming an "impenetrable Cyber Security unit so that election hacking, & many other negative things, will be guarded and safe."

The admission alarmed some politicians, who said it seemed to show Trump trusted Putin's word over that of senior US intelligence officials. Republican Sen. Marco Rubio of Florida quipped that "partnering with Putin on a 'Cyber Security Unit' is akin to partnering with Assad on a 'Chemical Weapons Unit,'" referring to Syrian President Bashar al-Assad.

During their meeting, Trump and Putin also brokered an open-ended cease-fire in southern Syria, earning some praise. However, experts have said that the cease-fire is virtually unenforceable and that no cease-fire during the six-year-old Syrian war has lasted longer than six months.