The dollar rose to a three-week high on Friday, getting some safe-haven bids, as risk appetite for higher-yielding currencies took a step back amid renewed uncertainty about the rollback of existing tariffs, a major component of a preliminary US-China trade deal.

The yen, another safe haven, rose as well.

US President Donald Trump on Friday further heightened the uncertainty, saying he has not agreed to roll back tariffs.

His comments came a day after US and Chinese officials reportedly agreed to roll back tariffs on each others' goods in a "phase one" trade deal if it is completed.

But a report also on Thursday seemed to contradict that news, with multiple sources familiar with the talks saying the rollback faces fierce internal opposition at the White House and from outside advisers. The idea of a tariff rollback was not part of the original October "handshake" deal between Chinese Vice Premier Liu He and Trump, these sources said.

In midmorning trading, the dollar index rose 0.2% to 98.329 after earlier hitting a three-week high, led by gain against the euro, which dipped 0.2% to $1.1024.

The dollar, however, fell 0.1% against the safe-haven yen to 109.18 yen

The Canadian dollar, meanwhile, fell against the greenback after data showed the Canadian job market stagnated unexpectedly in October, losing 1,800 net positions, while the unemployment rate remained at 5.5%. The US dollar was last up 0.5% at C$1.3235.