As Chinese President Xi Jinping landed in Seattle on Tuesday to begin a week-long US visit, the focus is also on US President Barack Obama who is being accused by his Republican critics of showing "weakness" by delaying sanctions on Beijing for Chinese cyber attacks on businesses and government agencies at least for the duration of Xi's visit.

"We have to do something," House Homeland Security Committee Chairman Michael McCaul, R-Texas, told The Hill. "We can't have no response [to Chinese cyber attacks]. And this administration has absolutely failed to put any sort of consequence on their actions."

For weeks, Obama administration officials had been making plans to freeze Chinese companies' and individuals' assets and ban their dealings in the United States unless Beijing takes concrete steps to end its cyber attacks on American targets.

However, the White House suddenly changed tack and announced that it was delaying sanctions after US and Chinese officials held four days of secret cybersecurity talks, according to The Washington Post.

"I understand about quiet diplomacy, but this has been going on for far too long and I think the Chinese government has been far too complicit in this," Senate Homeland Security Committee Chairman Ron Johnson, R-Wisconsin, said.

The Republican presidential candidates were quick to pounce on Obama's show of weakness.

"I win against China," Trump told a South Carolina rally recently. "You can win against China if you're smart, but our people don't have a clue."

Former Florida Gov. Jeb Bush blasted Obama during Wednesday's Republican debates on the issue as he pressed for "offensive tactics" and "super sanctions" against Chinese interests in response to the Chinese cyber attacks.

Wisconsin Gov. Scott Walker even called on Obama to cancel Xi's official state visit.

Obama administration officials said they have proof that China is behind the hacking at the Office of Personnel Management that exposed more than 22 million people's personal data, including security clearance forms.

Despite this, Democratic leaders are backing Obama, saying he made the right decision to postpone sanctions on China.

"I had the urge that they not put sanctions in place concurrent with President Xi's visit," California Rep. Adam Schiff, top Democrat on the the House Intelligence Committee's told The Hill. "I thought that would just be so in your face as to be counter-productive—not only on the cyber issue, but on a raft of other issues."

White House spokesman Josh Earnest said Obama has not turn a blind eye to such crucial issue and in fact had been "pretty blunt'' in describing the US concerns with China's behaviour in cyberspace.