Washington: Both US' presumptive presidential nominees Hillary Clinton and Donald Trump are gaining steam among their own parties, but remain unfavorable nationally, a poll issued on Monday found.

According to the poll conducted by research-based, global performance-management firm Gallup, since clinching the Democratic nomination earlier this month, Clinton's favourable rating among Democrats and Democratic-leaning independents has been up slightly to 71 per cent, compared with 68 per cent in April and May, Xinhua news agency reported.