Senior OPEC and Russian oil industry officials stepped up vague talk on Monday of possible joint action to remedy one of the worst supply gluts in decades, while Saudi Arabia signaled its resolve to allow the market to balance itself. The latest volley of comments highlighted the intensifying pressure of $30 a barrel oil prices on cash-strapped countries such as Russia, but did not appear to tilt the scales meaningfully towards any concerted action to reverse the price crash, an idea repeatedly mooted but dismissed for over a year.